Climate averages 1991–2020
Colchester weather
in September.
A mild, moderately wet month: the 4th warmest and the 4th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Colchester: daytime highs average 18.1°C and nights cool to about 12.3°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 52 mm of rain on roughly 10 days, which makes September a moderately wet month (the 4th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 43 min on an average September day.
The nearest other city in this atlas is Ipswich (26 km away). In September its highs average 18.1°C, about as warm as Colchester, with 54 mm of rain.
Among the 143 cities listed in the United Kingdom, Colchester ranks joint 30th of 143 for the warmest September highs and joint 37th of 143 for the driest September (rainfall, lowest first). The mean September high of those 143 cities is 17.3°C; Colchester is 0.8°C warmer than that mean.
From September to October, average highs fall by 3.8°C to 14.3°C, and monthly rainfall rises from 52 mm to 64 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Colchester climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 7.1°C3.0°C | 3.0°C | 57 | 12.1 | 8.38 h |
| February | 7.4°C2.8°C | 2.8°C | 47 | 9.8 | 9.910 h |
| March | 9.5°C4.0°C | 4.0°C | 43 | 10.2 | 11.812 h |
| April | 12.2°C5.9°C | 5.9°C | 45 | 10.4 | 13.914 h |
| May | 15.3°C8.9°C | 8.9°C | 53 | 10.0 | 15.616 h |
| June | 18.2°C11.9°C | 11.9°C | 57 | 10.8 | 16.617 h |
| July | 20.7°C14.2°C | 14.2°C | 58 | 11.8 | 16.216 h |
| August | 20.7°C14.4°C | 14.4°C | 64 | 10.7 | 14.715 h |
| September, selected | 18.1°C12.3°C | 12.3°C | 52 | 10.3 | 12.713 h |
| October | 14.3°C9.5°C | 9.5°C | 64 | 11.4 | 10.711 h |
| November | 10.3°C6.0°C | 6.0°C | 61 | 11.1 | 8.99 h |
| December | 7.6°C3.7°C | 3.7°C | 62 | 11.6 | 7.98 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Ipswich in SeptemberUnited Kingdom · 26 kmHigh 18.1°C · Low 12.1°C · 54 mm rain
- Chelmsford in SeptemberUnited Kingdom · 34 kmHigh 18.3°C · Low 11.8°C · 46 mm rain
- Southend-on-Sea in SeptemberUnited Kingdom · 41 kmHigh 18.1°C · Low 12.5°C · 56 mm rain
- Basildon in SeptemberUnited Kingdom · 47 kmHigh 18.2°C · Low 12.1°C · 45 mm rain
- Harlow in SeptemberUnited Kingdom · 56 kmHigh 18.3°C · Low 11.0°C · 48 mm rain
- Gillingham in SeptemberUnited Kingdom · 61 kmHigh 18.3°C · Low 11.9°C · 45 mm rain
- Grays in SeptemberUnited Kingdom · 61 kmHigh 18.5°C · Low 11.8°C · 45 mm rain
- Dagenham in SeptemberUnited Kingdom · 63 kmHigh 18.5°C · Low 11.7°C · 45 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Colchester) is explained once on the Colchester year overview and on the Sources, method and limits page.