Portsmouth weather forecast
UK towns · Hampshire, England · 50.82°N 1.09°W
Portsmouth, in Hampshire, England, has its warmest weather in August, when daytime temperatures average 21.3°C, while January nights are the coldest at around 3.5°C. The town sees roughly 953mm of rain a year; October is normally the wettest month and April the driest. Figures are averaged from 2020–2024 observations.
Climate averages
| Month | Avg high | Avg low | Rain | Rain days |
|---|---|---|---|---|
| Jan | 8.3° | 3.5° | 80mm | 12 |
| Feb | 9.8° | 4.9° | 91mm | 14 |
| Mar | 10.6° | 5.3° | 79mm | 14 |
| Apr | 13° | 6° | 49mm | 8 |
| May | 16.3° | 9.3° | 58mm | 11 |
| Jun | 19.7° | 12.6° | 59mm | 11 |
| Jul | 20.8° | 14.5° | 64mm | 12 |
| Aug | 21.3° | 14.9° | 63mm | 11 |
| Sep | 19.5° | 13.2° | 80mm | 12 |
| Oct | 15.8° | 11.1° | 137mm | 17 |
| Nov | 11.9° | 7.3° | 94mm | 12 |
| Dec | 9.5° | 5.5° | 99mm | 14 |
Seasons in Portsmouth
Spring (March–May). Daytime highs in Portsmouth climb from 10.6°C in March to 16.3°C by May, while nights ease from 5.3°C to 9.3°C. The season brings around 186mm of rain in total.
Summer (June–August). The warmest stretch of the year: afternoons average 20.6°C, peaking in August at 21.3°C. June is usually the driest of the summer months (59mm over ~11 rainy days). Around the June solstice, Portsmouth gets roughly 16.3 hours of daylight.
Autumn (September–November). Daytime temperatures fall from 19.5°C in September to 11.9°C by November, and rainfall builds to its annual peak — October is the wettest month of the year (137mm).
Winter (December–February). Nights average 4.6°C, with January the coldest month (average low 3.5°C, daytime high 8.3°C). Expect about 40 days with measurable rain over the three months, and only around 7.7 hours of daylight in mid-December.
How Portsmouth compares
| Portsmouth | UK town average | |
|---|---|---|
| Annual rainfall | 953mm | 1054mm |
| Rainy days per year | 148 | 167 |
| Summer daytime high | 20.6°C | 19.7°C |
| Winter night low | 4.6°C | 3.4°C |
Portsmouth is about 10% drier than the average for the 121 UK towns tracked on this site (1054mm), based on 2020–2024 monthly normals.
Portsmouth weather FAQs
What is the warmest month in Portsmouth?
August is typically the warmest month in Portsmouth, with average daytime highs of 21.3°C. Summer afternoons (June–August) average around 20.6°C.
What is the wettest month in Portsmouth?
October is usually the wettest month, with around 137mm of rain over roughly 17 rainy days. April is typically the driest (49mm).
How much does it rain in Portsmouth per year?
Portsmouth receives roughly 953mm of precipitation per year, spread over about 148 days with at least 1mm of rain (based on 2020–2024 observations).
How cold are winters in Portsmouth?
Winter nights (December–February) in Portsmouth average around 4.6°C, with January typically the coldest month (average low 3.5°C).
When is the best time to visit Portsmouth for good weather?
Late spring and summer offer the most reliable weather in Portsmouth. June is typically the driest of the warm months (59mm of rain), while August is the warmest, averaging 21.3°C by day — and near the June solstice there are around 16 hours of daylight to enjoy.
How does Portsmouth's weather compare with the rest of the UK?
Portsmouth receives 953mm of rain a year, about 10% drier than the average for the 121 UK towns tracked on this site (1054mm). Summer daytime highs average 20.6°C against a UK-town average of 19.7°C, and winter nights average 4.6°C versus 3.4°C.
Is it going to rain in Portsmouth?
For up-to-the-minute rain tracking, check the live rain radar — as a long-term guide, Portsmouth averages 148 rainy days a year, with October the wettest month (137mm) and April the driest (49mm).
What is the 7-day forecast for Portsmouth?
See the live hourly and 7-day forecast for day-by-day temperatures and rain chance. The figures on this page are long-term climate averages from 2020–2024, not the live forecast.