Climate averages 1991–2020

Southampton weather
in August.

A mild, moderately wet month: the 2nd warmest and the 8th driest of the year.

Long-term climate patterns, not a forecast for a particular trip.

Average high 20.4°C Daytime mean, August

Average low 13.9°C Night-time mean, August

Rainfall 65 mm 10 days with ≥1 mm

Daylight 15 h Sunrise to sunset, per day

August is a mild month in Southampton: daytime highs average 20.4°C and nights cool to about 13.9°C. By daytime temperature it is the 2nd warmest of the 12 months.

Expect about 65 mm of rain on roughly 10 days, which makes August a moderately wet month (the 8th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 33 min on an average August day.

The nearest other city in this atlas is Portsmouth (25 km away). In August its highs average 20.6°C, about as warm as Southampton, with 64 mm of rain.

Among the 143 cities listed in the United Kingdom, Southampton ranks joint 50th of 143 for the warmest August highs and joint 71st of 143 for the driest August (rainfall, lowest first). The mean August high of those 143 cities is 19.7°C; Southampton is 0.7°C warmer than that mean.

From August to September, average highs fall by 2.3°C to 18.1°C, and monthly rainfall falls from 65 mm to 54 mm.

The annual picture

August 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

Southampton climate table

1991–2020

Monthly climate averages for Southampton, 1991–2020
Month	Average highHigh / low	Average low	Rainfall mm/month	Rain days ≥1 mm/day	Daylight hours/dayDaylight h/day
January	7.8°C3.5°C	3.5°C	67	11.5	8.58 h
February	8.0°C3.2°C	3.2°C	51	10.2	10.010 h
March	10.2°C4.3°C	4.3°C	48	10.1	11.812 h
April	12.8°C5.9°C	5.9°C	56	11.1	13.814 h
May	15.9°C8.8°C	8.8°C	57	10.0	15.515 h
June	18.6°C11.7°C	11.7°C	54	10.0	16.416 h
July	20.7°C13.8°C	13.8°C	53	10.0	16.016 h
August, selected	20.4°C13.9°C	13.9°C	65	10.4	14.615 h
September	18.1°C12.0°C	12.0°C	54	9.3	12.713 h
October	14.5°C9.6°C	9.6°C	75	11.6	10.811 h
November	10.8°C6.4°C	6.4°C	75	11.7	9.09 h
December	8.3°C4.2°C	4.2°C	71	11.4	8.08 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

August in nearby cities

Distance from Southampton

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 Southampton) is explained once on the Southampton year overview and on the Sources, method and limits page.