Welwyn Hatfield East of England

Postcode districts

Choose a district to see every street in it. A district can cross an authority boundary; the count is of this authority's streets in it. Sales: HM Land Registry Price Paid Data, standard sales in the twelve months to 28 August 2026, by the district of the postcode.

Climate

Worked out for one point: the average position of Welwyn Hatfield's postcodes, near Mill Green. Across an authority the climate can differ by a degree or two, more on high ground and by the sea.

Over 1991 to 2020, July days here averaged a high of 23°C, and February nights a low of 2°C. About 622 mm of rain fell in a year, most in November. A typical year had 41 days of air frost and 20 days above 25°C, and 15 days with 10 mm of rain or more.

Source: Met Office, HadUK-Grid climate averages for 1991 to 2020, from weather station records spread onto a grid. Rainfall, frost and summer days are for the 2 km square around the middle of Welwyn Hatfield's homes, near Mill Green; daily highs and lows are published for 12 km squares only, so they have been moved by the difference between the 2 km square's average temperature and the 12 km square's. These are long-term averages, not a forecast: recent years have been warmer, and a valley bottom or a hilltop in the same square can differ by a degree or two.

Daylight through the year

On the shortest day, 21 December, the sun rises at 08:05 and sets at 15:52: 7 h 47 min of daylight. On the longest, 21 June, it rises at 04:41 and sets at 21:23: 16 h 42 min.

Worked out from the latitude and longitude of the middle of Welwyn Hatfield's homes, near Mill Green, in UK clock time (British Summer Time from the last Sunday in March to the last Sunday in October), for flat ground with a clear horizon. Hills, buildings and trees make the sun appear later and set earlier, and which way the windows face decides how much of it comes in.

Earthquakes

Since 1970 the British Geological Survey has recorded 6 earthquakes of magnitude 2 or more within 50 km (31 miles) of the middle of Welwyn Hatfield's homes, near Mill Green; 2 of them were magnitude 3 or more. The largest was magnitude 3.5, centred near Leighton Buzzard, Beds, 40.3 km (25 miles) north-west, on 8 September 2020. The most recent was magnitude 2.3, near Sawston, Cambridgeshire, on 8 August 2022.

What the sizes mean: magnitude 2 is rarely felt and is found by instruments; magnitude 3 is often felt close by, like a heavy lorry passing, and does no harm; magnitude 4 is felt widely and can rattle windows and knock things off shelves, occasionally cracking plaster near the centre; magnitude 5 or more is rare in Britain, a few in fifty years, and can damage chimneys and old walls close to the centre. Each step up is about 30 times more energy.

Source: British Geological Survey earthquake database, every earthquake of magnitude 2 or more since 1970, as held in November 2026. Contains British Geological Survey materials © UKRI 2026. Distances are in a straight line to where BGS places the centre of each earthquake, which for older ones can be a few kilometres out. This is a record of earthquakes, not of the ground under the middle of Welwyn Hatfield's homes, near Mill Green: for coal mining and ground stability, ask your conveyancer about a mining search.