SG4 postcode district: Hitchin and around, Hertfordshire

SG4 is a postcode district in Hertfordshire, with 906 postcodes in use in 4 sectors. It has postcodes in Hitchin, Codicote and Stevenage. It is split between 3 councils: North Hertfordshire (900 postcodes), Stevenage (5) and Welwyn Hatfield (1).

Postcodes in use
906
Sectors
4
Councils
3 councils
Places
3 places

Source: Office for National Statistics (ONS) Postcode Directory, August 2026, loaded 20 October 2026. See all our data sources

Every postcode in SG4, by flood risk

Map of every postcode in SG4, by flood risk Of the 906 postcodes in SG4 that ONS places, 21 have a home or business at high risk, 13 are at medium risk at worst, 25 are at low risk at worst and 847 are not on the Environment Agency's at-risk list. One group of postcodes at high or medium risk is outlined: 9 postcodes at high or medium risk. Places named: Hitchin, Stevenage, Woolmer Green, Knebworth, Codicote. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 2.5 km. A1(M)A507 SG4 0AB: not on the flood risk listSG4 0AE: not on the flood risk listSG4 0AG: not on the flood risk listSG4 0AH: not on the flood risk listSG4 0AL: not on the flood risk listSG4 0AN: not on the flood risk listSG4 0AP: not on the flood risk listSG4 0BD: not on the flood risk listSG4 0BE: not on the flood risk listSG4 0BH: not on the flood risk listSG4 0BL: not on the flood risk listSG4 0BP: not on the flood risk listSG4 0BQ: not on the flood risk listSG4 0DH: not on the flood risk listSG4 0DL: not on the flood risk listSG4 0DN: not on the flood risk listSG4 0DP: not on the flood risk listSG4 0DR: not on the flood risk listSG4 0DS: not on the flood risk listSG4 0DW: not on the flood risk listSG4 0EA: not on the flood risk listSG4 0ED: not on the flood risk listSG4 0EL: not on the flood risk listSG4 0EP: not on the flood risk listSG4 0ER: not on the flood risk listSG4 0ES: not on the flood risk listSG4 0EX: not on the flood risk listSG4 0FR: not on the flood risk listSG4 0HB: not on the flood risk listSG4 0HL: not on the flood risk listSG4 0HS: not on the flood risk listSG4 0JD: not on the flood risk listSG4 0JN: not on the flood risk listSG4 0JR: not on the flood risk listSG4 0JS: not on the flood risk listSG4 0JT: not on the flood risk listSG4 0JU: not on the flood risk listSG4 0LA: not on the flood risk listSG4 0LB: not on the flood risk listSG4 0LD: not on the flood risk listSG4 0LF: not on the flood risk listSG4 0LJ: not on the flood risk listSG4 0LN: not on the flood risk listSG4 0LP: not on the flood risk listSG4 0LQ: not on the flood risk listSG4 0LR: not on the flood risk listSG4 0LS: not on the flood risk listSG4 0LT: not on the flood risk listSG4 0LU: not on the flood risk listSG4 0LX: not on the flood risk listSG4 0LZ: not on the flood risk listSG4 0NE: not on the flood risk listSG4 0NH: not on the flood risk listSG4 0NJ: not on the flood risk listSG4 0NL: not on the flood risk listSG4 0NN: not on the flood risk listSG4 0NP: not on the flood risk listSG4 0NS: not on the flood risk listSG4 0NT: not on the flood risk listSG4 0NX: not on the flood risk listSG4 0NZ: not on the flood risk listSG4 0PA: not on the flood risk listSG4 0PB: not on the flood risk listSG4 0PD: not on the flood risk listSG4 0PF: not on the flood risk listSG4 0PJ: not on the flood risk listSG4 0PL: not on the flood risk listSG4 0PU: not on the flood risk listSG4 0PZ: not on the flood risk listSG4 0QA: not on the flood risk listSG4 0QD: not on the flood risk listSG4 0QE: not on the flood risk listSG4 0QF: not on the flood risk listSG4 0QG: not on the flood risk listSG4 0QH: not on the flood risk listSG4 0QL: not on the flood risk listSG4 0QQ: not on the flood risk listSG4 0QR: not on the flood risk listSG4 0QU: not on the flood risk listSG4 0QW: not on the flood risk listSG4 0QX: not on the flood risk listSG4 0QY: not on the flood risk listSG4 0QZ: not on the flood risk listSG4 0RA: not on the flood risk listSG4 0RE: not on the flood risk listSG4 0RG: not on the flood risk listSG4 0RJ: not on the flood risk listSG4 0RS: not on the flood risk listSG4 0SA: not on the flood risk listSG4 0SB: not on the flood risk listSG4 0SE: not on the flood risk listSG4 0SL: not on the flood risk listSG4 0TJ: not on the flood risk listSG4 0TP: not on the flood risk listSG4 0TS: not on the flood risk listSG4 0TW: not on the flood risk listSG4 0TY: not on the flood risk listSG4 0TZ: not on the flood risk listSG4 0UB: not on the flood risk listSG4 0UD: not on the flood risk listSG4 0WW: not on the flood risk listSG4 7AA: not on the flood risk listSG4 7AB: not on the flood risk listSG4 7AE: not on the flood risk listSG4 7AG: not on the flood risk listSG4 7AH: not on the flood risk listSG4 7AJ: not on the flood risk listSG4 7AL: not on the flood risk listSG4 7AP: not on the flood risk listSG4 7AQ: not on the flood risk listSG4 7AR: not on the flood risk listSG4 7AS: not on the flood risk listSG4 7AU: not on the flood risk listSG4 7AW: not on the flood risk listSG4 7AY: not on the flood risk listSG4 7AZ: not on the flood risk listSG4 7BA: not on the flood risk listSG4 7BB: not on the flood risk listSG4 7BD: not on the flood risk listSG4 7BE: not on the flood risk listSG4 7BF: not on the flood risk listSG4 7BG: not on the flood risk listSG4 7BH: not on the flood risk listSG4 7BJ: not on the flood risk listSG4 7BL: not on the flood risk listSG4 7BN: not on the flood risk listSG4 7BS: not on the flood risk listSG4 7BT: not on the flood risk listSG4 7BU: not on the flood risk listSG4 7BW: not on the flood risk listSG4 7BX: not on the flood risk listSG4 7BZ: not on the flood risk listSG4 7DA: not on the flood risk listSG4 7DD: not on the flood risk listSG4 7DJ: not on the flood risk listSG4 7DL: not on the flood risk listSG4 7DQ: not on the flood risk listSG4 7DR: not on the flood risk listSG4 7DS: not on the flood risk listSG4 7DT: not on the flood risk listSG4 7DU: not on the flood risk listSG4 7DW: not on the flood risk listSG4 7DX: not on the flood risk listSG4 7DZ: not on the flood risk listSG4 7EA: not on the flood risk listSG4 7EB: not on the flood risk listSG4 7ED: not on the flood risk listSG4 7EE: not on the flood risk listSG4 7EG: not on the flood risk listSG4 7EH: not on the flood risk listSG4 7EJ: not on the flood risk listSG4 7EL: not on the flood risk listSG4 7EP: not on the flood risk listSG4 7EQ: not on the flood risk listSG4 7ER: not on the flood risk listSG4 7ES: not on the flood risk listSG4 7ET: not on the flood risk listSG4 7EW: not on the flood risk listSG4 7EX: not on the flood risk listSG4 7EY: not on the flood risk listSG4 7EZ: not on the flood risk listSG4 7FA: not on the flood risk listSG4 7FB: not on the flood risk listSG4 7HD: not on the flood risk listSG4 7HE: not on the flood risk listSG4 7HG: not on the flood risk listSG4 7HH: not on the flood risk listSG4 7HJ: not on the flood risk listSG4 7HL: not on the flood risk listSG4 7HN: not on the flood risk listSG4 7HP: not on the flood risk listSG4 7HT: not on the flood risk listSG4 7HW: not on the flood risk listSG4 7HX: not on the flood risk listSG4 7JA: not on the flood risk listSG4 7JD: not on the flood risk listSG4 7JG: not on the flood risk listSG4 7JJ: not on the flood risk listSG4 7JL: not on the flood risk listSG4 7JN: not on the flood risk listSG4 7JP: not on the flood risk listSG4 7JR: not on the flood risk listSG4 7JT: not on the flood risk listSG4 7LD: not on the flood risk listSG4 7LE: not on the flood risk listSG4 7LH: not on the flood risk listSG4 7LJ: not on the flood risk listSG4 7LN: not on the flood risk listSG4 7LP: not on the flood risk listSG4 7LS: not on the flood risk listSG4 7LU: not on the flood risk listSG4 7NF: not on the flood risk listSG4 7NG: not on the flood risk listSG4 7NH: not on the flood risk listSG4 7NJ: not on the flood risk listSG4 7NL: not on the flood risk listSG4 7NN: not on the flood risk listSG4 7NR: not on the flood risk listSG4 7NS: not on the flood risk listSG4 7NT: not on the flood risk listSG4 7NZ: not on the flood risk listSG4 7PA: not on the flood risk listSG4 7PB: not on the flood risk listSG4 7PD: not on the flood risk listSG4 7PE: not on the flood risk listSG4 7PF: not on the flood risk listSG4 7PG: not on the flood risk listSG4 7PH: not on the flood risk listSG4 7PL: not on the flood risk listSG4 7PP: not on the flood risk listSG4 7PS: not on the flood risk listSG4 7PT: not on the flood risk listSG4 7PW: not on the flood risk listSG4 7QA: not on the flood risk listSG4 7QB: not on the flood risk listSG4 7QE: not on the flood risk listSG4 7QG: not on the flood risk listSG4 7QJ: not on the flood risk listSG4 7QL: not on the flood risk listSG4 7QP: not on the flood risk listSG4 7QR: not on the flood risk listSG4 7QS: not on the flood risk listSG4 7QT: not on the flood risk listSG4 7QU: not on the flood risk listSG4 7QZ: not on the flood risk listSG4 7RA: not on the flood risk listSG4 7RB: not on the flood risk listSG4 7RD: not on the flood risk listSG4 7RG: not on the flood risk listSG4 7RH: not on the flood risk listSG4 7RJ: not on the flood risk listSG4 7RL: not on the flood risk listSG4 7RN: not on the flood risk listSG4 7RQ: not on the flood risk listSG4 7RS: not on the flood risk listSG4 7RU: not on the flood risk listSG4 7RW: not on the flood risk listSG4 7RX: not on the flood risk listSG4 7RY: not on the flood risk listSG4 7RZ: not on the flood risk listSG4 7SA: not on the flood risk listSG4 7SB: not on the flood risk listSG4 7SJ: not on the flood risk listSG4 7SL: not on the flood risk listSG4 7SN: not on the flood risk listSG4 7SW: not on the flood risk listSG4 7TB: not on the flood risk listSG4 7TD: not on the flood risk listSG4 7TE: not on the flood risk listSG4 7TP: not on the flood risk listSG4 7TR: not on the flood risk listSG4 7TS: not on the flood risk listSG4 7TT: not on the flood risk listSG4 7TU: not on the flood risk listSG4 7TY: not on the flood risk listSG4 7TZ: not on the flood risk listSG4 7UA: not on the flood risk listSG4 7UE: not on the flood risk listSG4 7UF: not on the flood risk listSG4 7UH: not on the flood risk listSG4 7UJ: not on the flood risk listSG4 7UQ: not on the flood risk listSG4 7UW: not on the flood risk listSG4 7WH: not on the flood risk listSG4 8AB: not on the flood risk listSG4 8AD: not on the flood risk listSG4 8AE: not on the flood risk listSG4 8AF: not on the flood risk listSG4 8AH: not on the flood risk listSG4 8AJ: not on the flood risk listSG4 8AL: not on the flood risk listSG4 8AP: not on the flood risk listSG4 8AQ: not on the flood risk listSG4 8AR: not on the flood risk listSG4 8AT: not on the flood risk listSG4 8AU: not on the flood risk listSG4 8AW: not on the flood risk listSG4 8BE: not on the flood risk listSG4 8BJ: not on the flood risk listSG4 8BL: not on the flood risk listSG4 8BN: not on the flood risk listSG4 8BP: not on the flood risk listSG4 8BQ: not on the flood risk listSG4 8BS: not on the flood risk listSG4 8BT: not on the flood risk listSG4 8BU: not on the flood risk listSG4 8BW: not on the flood risk listSG4 8BX: not on the flood risk listSG4 8BZ: not on the flood risk listSG4 8DA: not on the flood risk listSG4 8DB: not on the flood risk listSG4 8DD: not on the flood risk listSG4 8DE: not on the flood risk listSG4 8DF: not on the flood risk listSG4 8DG: not on the flood risk listSG4 8DH: not on the flood risk listSG4 8DJ: not on the flood risk listSG4 8DL: not on the flood risk listSG4 8DN: not on the flood risk listSG4 8DQ: not on the flood risk listSG4 8DR: not on the flood risk listSG4 8DU: not on the flood risk listSG4 8DW: not on the flood risk listSG4 8DX: not on the flood risk listSG4 8DY: not on the flood risk listSG4 8DZ: not on the flood risk listSG4 8EB: not on the flood risk listSG4 8EE: not on the flood risk listSG4 8EF: not on the flood risk listSG4 8EG: not on the flood risk listSG4 8EH: not on the flood risk listSG4 8EJ: not on the flood risk listSG4 8EL: not on the flood risk listSG4 8EN: not on the flood risk listSG4 8EP: not on the flood risk listSG4 8EQ: not on the flood risk listSG4 8ER: not on the flood risk listSG4 8ES: not on the flood risk listSG4 8ET: not on the flood risk listSG4 8EU: not on the flood risk listSG4 8EW: not on the flood risk listSG4 8EX: not on the flood risk listSG4 8EY: not on the flood risk listSG4 8EZ: not on the flood risk listSG4 8FN: not on the flood risk listSG4 8GG: not on the flood risk listSG4 8HA: not on the flood risk listSG4 8HB: not on the flood risk listSG4 8HD: not on the flood risk listSG4 8HE: not on the flood risk listSG4 8HF: not on the flood risk listSG4 8HG: not on the flood risk listSG4 8HH: not on the flood risk listSG4 8HJ: not on the flood risk listSG4 8HL: not on the flood risk listSG4 8HN: not on the flood risk listSG4 8HP: not on the flood risk listSG4 8HR: not on the flood risk listSG4 8HX: not on the flood risk listSG4 8HZ: not on the flood risk listSG4 8JA: not on the flood risk listSG4 8JB: not on the flood risk listSG4 8JD: not on the flood risk listSG4 8JE: not on the flood risk listSG4 8JJ: not on the flood risk listSG4 8JN: not on the flood risk listSG4 8JP: not on the flood risk listSG4 8JQ: not on the flood risk listSG4 8JS: not on the flood risk listSG4 8JT: not on the flood risk listSG4 8JU: not on the flood risk listSG4 8JX: not on the flood risk listSG4 8JY: not on the flood risk listSG4 8LA: not on the flood risk listSG4 8LB: not on the flood risk listSG4 8LD: not on the flood risk listSG4 8LE: not on the flood risk listSG4 8LF: not on the flood risk listSG4 8LH: not on the flood risk listSG4 8LJ: not on the flood risk listSG4 8LL: not on the flood risk listSG4 8LN: not on the flood risk listSG4 8LP: not on the flood risk listSG4 8LR: not on the flood risk listSG4 8LS: not on the flood risk listSG4 8LT: not on the flood risk listSG4 8LU: not on the flood risk listSG4 8LW: not on the flood risk listSG4 8NE: not on the flood risk listSG4 8NG: not on the flood risk listSG4 8NH: not on the flood risk listSG4 8NJ: not on the flood risk listSG4 8NL: not on the flood risk listSG4 8NP: not on the flood risk listSG4 8NQ: not on the flood risk listSG4 8NS: not on the flood risk listSG4 8NT: not on the flood risk listSG4 8NU: not on the flood risk listSG4 8NW: not on the flood risk listSG4 8NX: not on the flood risk listSG4 8NY: not on the flood risk listSG4 8NZ: not on the flood risk listSG4 8PA: not on the flood risk listSG4 8PB: not on the flood risk listSG4 8PD: not on the flood risk listSG4 8PE: not on the flood risk listSG4 8PF: not on the flood risk listSG4 8PH: not on the flood risk listSG4 8PJ: not on the flood risk listSG4 8PL: not on the flood risk listSG4 8PN: not on the flood risk listSG4 8PP: not on the flood risk listSG4 8PT: not on the flood risk listSG4 8PU: not on the flood risk listSG4 8PY: not on the flood risk listSG4 8PZ: not on the flood risk listSG4 8QA: not on the flood risk listSG4 8QB: not on the flood risk listSG4 8QE: not on the flood risk listSG4 8QG: not on the flood risk listSG4 8QH: not on the flood risk listSG4 8QJ: not on the flood risk listSG4 8QN: not on the flood risk listSG4 8QP: not on the flood risk listSG4 8QS: not on the flood risk listSG4 8QT: not on the flood risk listSG4 8RA: not on the flood risk listSG4 8RD: not on the flood risk listSG4 8RG: not on the flood risk listSG4 8RH: not on the flood risk listSG4 8RJ: not on the flood risk listSG4 8RP: not on the flood risk listSG4 8RR: not on the flood risk listSG4 8RX: not on the flood risk listSG4 8SN: not on the flood risk listSG4 8SR: not on the flood risk listSG4 8SU: not on the flood risk listSG4 8SW: not on the flood risk listSG4 8SX: not on the flood risk listSG4 8SY: not on the flood risk listSG4 8SZ: not on the flood risk listSG4 8TA: not on the flood risk listSG4 8TB: not on the flood risk listSG4 8TD: not on the flood risk listSG4 8TF: not on the flood risk listSG4 8TG: not on the flood risk listSG4 8TH: not on the flood risk listSG4 8TJ: not on the flood risk listSG4 8TP: not on the flood risk listSG4 8TQ: not on the flood risk listSG4 8TR: not on the flood risk listSG4 8TS: not on the flood risk listSG4 8TY: not on the flood risk listSG4 8UA: not on the flood risk listSG4 8UF: not on the flood risk listSG4 8UG: not on the flood risk listSG4 8UN: not on the flood risk listSG4 8UR: not on the flood risk listSG4 8UU: not on the flood risk listSG4 8UW: not on the flood risk listSG4 8UX: not on the flood risk listSG4 8UY: not on the flood risk listSG4 8WP: not on the flood risk listSG4 8WT: not on the flood risk listSG4 8WW: not on the flood risk listSG4 8XA: not on the flood risk listSG4 8XB: not on the flood risk listSG4 8XH: not on the flood risk listSG4 8XJ: not on the flood risk listSG4 8XL: not on the flood risk listSG4 8XR: not on the flood risk listSG4 8XU: not on the flood risk listSG4 8XW: not on the flood risk listSG4 8XY: not on the flood risk listSG4 8XZ: not on the flood risk listSG4 8YA: not on the flood risk listSG4 8YB: not on the flood risk listSG4 8YE: not on the flood risk listSG4 8YF: not on the flood risk listSG4 8YL: not on the flood risk listSG4 8YN: not on the flood risk listSG4 8YS: not on the flood risk listSG4 8YU: not on the flood risk listSG4 8YZ: not on the flood risk listSG4 9AA: not on the flood risk listSG4 9AB: not on the flood risk listSG4 9AD: not on the flood risk listSG4 9AE: not on the flood risk listSG4 9AF: not on the flood risk listSG4 9AG: not on the flood risk listSG4 9AH: not on the flood risk listSG4 9AJ: not on the flood risk listSG4 9AN: not on the flood risk listSG4 9AP: not on the flood risk listSG4 9AR: not on the flood risk listSG4 9AS: not on the flood risk listSG4 9AT: not on the flood risk listSG4 9AU: not on the flood risk listSG4 9AW: not on the flood risk listSG4 9AX: not on the flood risk listSG4 9BA: not on the flood risk listSG4 9BB: not on the flood risk listSG4 9BD: not on the flood risk listSG4 9BG: not on the flood risk listSG4 9BH: not on the flood risk listSG4 9BJ: not on the flood risk listSG4 9BN: not on the flood risk listSG4 9BQ: not on the flood risk listSG4 9DD: not on the flood risk listSG4 9DE: not on the flood risk listSG4 9DG: not on the flood risk listSG4 9DH: not on the flood risk listSG4 9DJ: not on the flood risk listSG4 9DN: not on the flood risk listSG4 9DP: not on the flood risk listSG4 9DQ: not on the flood risk listSG4 9DT: not on the flood risk listSG4 9DU: not on the flood risk listSG4 9DW: not on the flood risk listSG4 9EA: not on the flood risk listSG4 9EG: not on the flood risk listSG4 9EH: not on the flood risk listSG4 9EJ: not on the flood risk listSG4 9EN: not on the flood risk listSG4 9EP: not on the flood risk listSG4 9EW: not on the flood risk listSG4 9EY: not on the flood risk listSG4 9FB: not on the flood risk listSG4 9FF: not on the flood risk listSG4 9FG: not on the flood risk listSG4 9FJ: not on the flood risk listSG4 9FL: not on the flood risk listSG4 9FN: not on the flood risk listSG4 9FP: not on the flood risk listSG4 9GD: not on the flood risk listSG4 9HD: not on the flood risk listSG4 9HF: not on the flood risk listSG4 9HH: not on the flood risk listSG4 9HJ: not on the flood risk listSG4 9HN: not on the flood risk listSG4 9HP: not on the flood risk listSG4 9HR: not on the flood risk listSG4 9HS: not on the flood risk listSG4 9HT: not on the flood risk listSG4 9HW: not on the flood risk listSG4 9HX: not on the flood risk listSG4 9HZ: not on the flood risk listSG4 9JA: not on the flood risk listSG4 9JF: not on the flood risk listSG4 9JH: not on the flood risk listSG4 9JL: not on the flood risk listSG4 9JQ: not on the flood risk listSG4 9JS: not on the flood risk listSG4 9LE: not on the flood risk listSG4 9LF: not on the flood risk listSG4 9LG: not on the flood risk listSG4 9LH: not on the flood risk listSG4 9LJ: not on the flood risk listSG4 9LL: not on the flood risk listSG4 9LU: not on the flood risk listSG4 9LX: not on the flood risk listSG4 9LY: not on the flood risk listSG4 9LZ: not on the flood risk listSG4 9NA: not on the flood risk listSG4 9NG: not on the flood risk listSG4 9NH: not on the flood risk listSG4 9NJ: not on the flood risk listSG4 9NL: not on the flood risk listSG4 9NP: not on the flood risk listSG4 9NR: not on the flood risk listSG4 9NZ: not on the flood risk listSG4 9PB: not on the flood risk listSG4 9PD: not on the flood risk listSG4 9PG: not on the flood risk listSG4 9PH: not on the flood risk listSG4 9PJ: not on the flood risk listSG4 9PL: not on the flood risk listSG4 9PN: not on the flood risk listSG4 9PS: not on the flood risk listSG4 9PW: not on the flood risk listSG4 9PX: not on the flood risk listSG4 9PY: not on the flood risk listSG4 9PZ: not on the flood risk listSG4 9QB: not on the flood risk listSG4 9QD: not on the flood risk listSG4 9QG: not on the flood risk listSG4 9QH: not on the flood risk listSG4 9QJ: not on the flood risk listSG4 9QN: not on the flood risk listSG4 9QQ: not on the flood risk listSG4 9QS: not on the flood risk listSG4 9QX: not on the flood risk listSG4 9QY: not on the flood risk listSG4 9QZ: not on the flood risk listSG4 9RA: not on the flood risk listSG4 9RB: not on the flood risk listSG4 9RD: not on the flood risk listSG4 9RE: not on the flood risk listSG4 9RG: not on the flood risk listSG4 9RH: not on the flood risk listSG4 9RJ: not on the flood risk listSG4 9RL: not on the flood risk listSG4 9RS: not on the flood risk listSG4 9RT: not on the flood risk listSG4 9RU: not on the flood risk listSG4 9RW: not on the flood risk listSG4 9RY: not on the flood risk listSG4 9SB: not on the flood risk listSG4 9SD: not on the flood risk listSG4 9SG: not on the flood risk listSG4 9SQ: not on the flood risk listSG4 9SS: not on the flood risk listSG4 9ST: not on the flood risk listSG4 9SU: not on the flood risk listSG4 9TB: not on the flood risk listSG4 9TP: not on the flood risk listSG4 9TT: not on the flood risk listSG4 9UJ: not on the flood risk listSG4 9UW: not on the flood risk listSG4 0AX: low flood risk at worstSG4 0BA: low flood risk at worstSG4 0BF: low flood risk at worstSG4 0BG: low flood risk at worstSG4 0BJ: low flood risk at worstSG4 0BS: low flood risk at worstSG4 0DA: low flood risk at worstSG4 0DU: low flood risk at worstSG4 0HN: low flood risk at worstSG4 0HP: low flood risk at worstSG4 0HX: low flood risk at worstSG4 0PE: low flood risk at worstSG4 7LG: low flood risk at worstSG4 7NE: low flood risk at worstSG4 7PQ: low flood risk at worstSG4 8SP: low flood risk at worstSG4 9EB: low flood risk at worstSG4 9EF: low flood risk at worstSG4 9JB: low flood risk at worstSG4 9JD: low flood risk at worstSG4 9NS: low flood risk at worstSG4 0AS: medium flood risk at worstSG4 0BX: medium flood risk at worstSG4 0BZ: medium flood risk at worstSG4 0JH: medium flood risk at worstSG4 0NG: medium flood risk at worstSG4 0PY: medium flood risk at worstSG4 0RF: medium flood risk at worstSG4 7HY: medium flood risk at worstSG4 7JY: medium flood risk at worstSG4 7LT: medium flood risk at worstSG4 8AG: medium flood risk at worstSG4 0AA: high flood riskSG4 0AF: high flood riskSG4 0AT: high flood riskSG4 0BU: high flood riskSG4 0DB: high flood riskSG4 0NF: high flood riskSG4 0PX: high flood riskSG4 7BQ: high flood riskSG4 7DP: high flood riskSG4 7LA: high flood riskSG4 7LR: high flood riskSG4 7LY: high flood riskSG4 7NP: high flood riskSG4 7NU: high flood riskSG4 8SL: high flood riskSG4 8ST: high flood riskSG4 9NU: high flood riskSG4 9NX: high flood riskSG4 9NY: high flood riskSG4 9QL: high flood risk HitchinStevenageWoolmer GreenKnebworthCodicote 9 postcodes at high or medium risk, outlined: this goes to SG4 0AT, the one with most homes and businesses at high risk9 postcodes at high or medium risk Map of every postcode in SG4, by flood risk Of the 906 postcodes in SG4 that ONS places, 21 have a home or business at high risk, 13 are at medium risk at worst, 25 are at low risk at worst and 847 are not on the Environment Agency's at-risk list. One group of postcodes at high or medium risk is outlined: 9 postcodes at high or medium risk. Places named: Hitchin, Stevenage, Woolmer Green, Knebworth. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 2.5 km. HitchinStevenageWoolmer GreenKnebworth
  • A home or business at high risk: 21
  • At medium risk at worst: 13
  • At low risk at worst: 25
  • At very low risk only: 0
  • Not on the at-risk list: 847
  • Outline: where 5 or more postcodes at high or medium risk lie together

Of the 906 postcodes in SG4 that ONS places, 21 have a home or business at high risk, 13 are at medium risk at worst, 25 are at low risk at worst and 847 are not on the Environment Agency's at-risk list.

Each mark is a postcode's centre point as ONS gives it, not a building. Press one to see its postcode and open its page. A dashed outline shows where 5 or more lie within 180 metres of each other. It is not a boundary, and no boundary is drawn. Where marks overlap, the one first in the key is drawn; the counts include every postcode.

The middle of its postcodes: latitude 51.9195, longitude -0.2594. Open this area on OpenStreetMap

Source: Office for National Statistics (ONS) Postcode Directory, August 2026, loaded 20 October 2026, the centre point of each postcode; flood risk: Environment Agency, published 6 July 2026; roads, rivers and built-up areas: Contains OS data © Crown copyright and database right 2026. Drawn by us. Street map: Ordnance Survey, OS Open Zoomstack, Open Government Licence v3.0, drawn with MapLibre. How we use them

The postcodes at high risk

21 postcodes here have a home or business at high risk. These are the 12 with the most homes and businesses at that risk.

Beside each: how many of its homes and businesses the Environment Agency puts at that risk.

SG4 0AT18 at high riskSG4 0AW11 at high riskSG4 9NX11 at high riskSG4 7LR10 at high riskSG4 0BU8 at high riskSG4 9NU6 at high riskSG4 0NF6 at high riskSG4 9NY6 at high riskSG4 7LY5 at high riskSG4 0AA3 at high riskSG4 7BQ2 at high riskSG4 7NP2 at high risk

Where the postcodes at high or medium risk lie together

  • 9 postcodes at high or medium risk, outlined on the map. SG4 0AT, is the one with most homes and businesses at high risk.

What broadband can you get in SG4?

Ofcom reports on 894 of the 906 postcodes in SG4. At 536 of them every home and business can get gigabit broadband, and at 15 some cannot get decent broadband (10 Mbit/s).

Postcodes where every home can get gigabit536 of 894
Postcodes where every home can get superfast788 of 894
Postcodes where some cannot get decent broadband15 of 894

Ofcom gives each postcode's share of homes and businesses, not how many there are, so these count postcodes. Each postcode page has its own figures. A provider's checker answers for one address.

Check one address on Ofcom's checker

Source: Ofcom, Connected Nations, Spring 2026, data for January 2026, Open Government Licence v3.0. How we use it

Is SG4 at risk of flooding?

59 of the 906 postcodes in SG4 have a home or business in an area at risk of flooding from rivers or the sea, the Environment Agency says. At those, it puts 207 homes and businesses in an area at high or medium risk.

Homes and businesses in an area at risk, at 59 of 906 postcodes High: 98Medium: 109Low: 255

High: 3.3% or more a year (1 in 30). Medium: 1% to 3.3% a year. Low: 0.1% to 1% a year. Very low: under 0.1% a year (1 in 1,000). Each band is the chance of flooding in any one year.

Homes and businesses in an area at risk of flooding from rivers or the sea, as the Environment Agency counts them, added up over the postcodes. It is for the land, not each building, and leaves out surface water, groundwater and sewers. Each postcode page has its own figures and its flood warning areas.

Source: Environment Agency, Risk of Flooding from Rivers and Sea (postcodes in areas at risk), published 6 July 2026, Open Government Licence v3.0. How we use it

What do homes sell for in SG4?

Homes in SG4 sold for a typical £475,000 in the 12 months to August 2026, across 388 sales, down 6.4% on the 12 months before, HM Land Registry's figures show.

£475,000 typical price, the 12 months to August 2026
12 months to August 2025
£507,500
12 months to August 2026
£475,000

▼ down 6.4% on the 12 months before

Detached£830,000 86 sales
Semi-detached£532,000 117 sales
Terraced£400,000 95 sales
Flat or maisonette£251,100 90 sales

Standard sales of homes at market value. A typical price is the median, the middle sale. Sales take weeks to be registered, so the last month or two are incomplete. Each postcode page gives the figure for its own postcode sector.

Source: HM Land Registry Price Paid Data, files dated 28 September 2026. Contains HM Land Registry data © Crown copyright and database right 2021. This data is licensed under the Open Government Licence v3.0. How we use it

Postcodes in SG4

Pick a sector, then a postcode. A sector is the district plus the next digit.

SG4 0184 postcodesSG4 7209 postcodesSG4 8281 postcodesSG4 9232 postcodes
UK postcode format explained

Places in SG4

Towns and villages with postcodes in SG4, and how many each has here.

Hitchin postcodes,422Codicote postcodes,74Stevenage postcodes,5

Who covers SG4

How many of the district's postcodes in use fall under each council, constituency and police force area.

Councils

What council am I in?

Constituencies

  • Hitchin742
  • Stevenage108
  • North East Hertfordshire55
  • Welwyn Hatfield1

Police force areas

  • Hertfordshire906

Next to SG4

SG3 postcode district SG5 postcode district All SG districts Hitchin postcodes

"Next to" is by number: the districts before and after SG4 in the SG area.

Check a postcode

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