Climate averages 1991–2020

Southampton weather
in March.

A cool, moderately wet month: the 9th warmest and the driest of the year.

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

Average high 10.2°C Daytime mean, March

Average low 4.3°C Night-time mean, March

Rainfall 48 mm 10 days with ≥1 mm

Daylight 12 h Sunrise to sunset, per day

March is a cool month in Southampton: daytime highs average 10.2°C and nights cool to about 4.3°C. By daytime temperature it is the 9th warmest of the 12 months.

Expect about 48 mm of rain on roughly 10 days, which makes March a moderately wet month (the driest month of the year). Daylight, from sunrise to sunset, lasts about 11 h 50 min on an average March day.

The nearest other city in this atlas is Portsmouth (25 km away). In March its highs average 10.3°C, about as warm as Southampton, with 50 mm of rain.

Among the 143 cities listed in the United Kingdom, Southampton ranks joint 16th of 143 for the warmest March highs and joint 65th of 143 for the driest March (rainfall, lowest first). The mean March high of those 143 cities is 9.5°C; Southampton is 0.6°C warmer than that mean.

From March to April, average highs rise by 2.7°C to 12.8°C, and monthly rainfall rises from 48 mm to 56 mm.

The annual picture

March 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, selected	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	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

March 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.