Weather in Portsmouth in September
In an average September, Portsmouth sees a daily high around 18°C and a low around 11°C, based on 1980–2026 of local climate records.
| Average high | 18°C |
|---|---|
| Typical high range | 15°C to 22°C |
| Average low | 11°C |
| Typical low range | 8°C to 15°C |
| Average daily precipitation | 3 mm |
September records
The most extreme September on record for each metric, across 1980–2026. For rainfall, the wettest and driest are by total September accumulation.
High
Highest
29°C
2023-09-09
Lowest
10°C
1993-09-27
Low
Highest
18°C
2026-09-03
Lowest
2°C
2003-09-24
Feels-like
Highest
33°C
2023-09-09
Lowest
-1°C
2003-09-24
Humidity
Highest
15.6 g/m³
2023-09-07
Lowest
5.7 g/m³
2003-09-24
Wind
Highest
50 km/h
1981-09-19
Lowest
6 km/h
1988-09-20
Gust
Highest
105 km/h
1981-09-19
Lowest
12 km/h
1985-09-24
Precip
Wettest
163 mm
2024
Driest
11 mm
2003
See Portsmouth's live weather grade →
Visiting Portsmouth in September? See how its comfort stacks up against where you live.
Compare Portsmouth with your city →