Climate averages 1991–2020

High Wycombe 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.

Average high 18.2°C Daytime mean, September

Average low 10.9°C Night-time mean, September

Rainfall 53 mm 9 days with ≥1 mm

Daylight 13 h Sunrise to sunset, per day

September is a mild month in High Wycombe: daytime highs average 18.2°C and nights cool to about 10.9°C. By daytime temperature it is the 4th warmest of the 12 months.

Expect about 53 mm of rain on roughly 9 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 Maidenhead (12 km away). In September its highs average 18.4°C, about as warm as High Wycombe, with 49 mm of rain.

Among the 143 cities listed in the United Kingdom, High Wycombe ranks joint 23rd of 143 for the warmest September highs and joint 42nd of 143 for the driest September (rainfall, lowest first). The mean September high of those 143 cities is 17.3°C; High Wycombe is 0.9°C warmer than that mean.

From September to October, average highs fall by 4.0°C to 14.2°C, and monthly rainfall rises from 53 mm to 61 mm.

The annual picture

September in context

30-year average

Average highAverage low°C

Monthly rainfall

Average total · mm

Averages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated

Every month, side by side

High Wycombe climate table

1991–2020

Monthly climate averages for High Wycombe, 1991–2020
Month	Average highHigh / low	Average low	Rainfall mm/month	Rain days ≥1 mm/day	Daylight hours/dayDaylight h/day
January	7.1°C2.1°C	2.1°C	55	11.2	8.48 h
February	7.7°C2.0°C	2.0°C	44	9.3	9.910 h
March	10.1°C3.2°C	3.2°C	45	10.2	11.812 h
April	13.0°C4.9°C	4.9°C	52	11.6	13.814 h
May	16.2°C7.9°C	7.9°C	57	10.4	15.616 h
June	19.0°C10.9°C	10.9°C	58	10.3	16.617 h
July	21.2°C13.1°C	13.1°C	59	10.9	16.216 h
August	20.8°C13.0°C	13.0°C	62	10.7	14.615 h
September, selected	18.2°C10.9°C	10.9°C	53	9.4	12.713 h
October	14.2°C8.2°C	8.2°C	61	11.4	10.711 h
November	10.0°C4.8°C	4.8°C	62	11.6	8.99 h
December	7.4°C2.7°C	2.7°C	58	10.9	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

Distance from High Wycombe

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 limits

How these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for High Wycombe) is explained once on the High Wycombe year overview and on the Sources, method and limits page.

Aylesbury lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.