Weather in Portsmouth for September 2026
Until now, September 2026 in Portsmouth has been nearly identical to the historical average, with a temperature of 19.3 °C (showing only a slight deviation of 0.4 °C).
The forecast for the next days in Portsmouth predicts temperatures to be around 19 °C, close to the historical average.
In general, the average temperature in Portsmouth at the beginning of September is 19.9 °C. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 17 °C by the end of September.
Portsmouth experiences heavy rainfall in September, with over 20 rainy days and an average total precipitation 82.8 mm.
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Portsmouth Weather September
Temperatures trend during September in Portsmouth
September weather in Portsmouth day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. |  Light rain shower | 19° /15° | 5.2 mm | 4 | |
| 2 Sept. | Light rain shower | 19° /15° | 2.4 mm | 4 | |
| 3 Sept. | Light rain shower | 20° /16° | 2.1 mm | 4 | |
| 4 Sept. | Light rain shower | 20° /14° | 2.5 mm | 4 | |
| 5 Sept. |  Sunny | 19° /14° | 3.9 mm | 5 | |
| 6 Sept. |  Overcast | 21° /16° | 4.7 mm | 4 | |
| 7 Sept. | Sunny | 21° /16° | 0.8 mm | 4 | |
| 8 Sept. | Patchy rain possible | 20° /15° | 6.5 mm | 4 | |
| 9 Sept. |  Partly cloudy | 19° /14° | 0.2 mm | 5 | |
| 10 Sept. | Partly cloudy | 20° /14° | 1.9 mm | 4 | |
| 11 Sept. | Patchy rain possible | 21° /17° | 1.4 mm | 4.3 | |
| 12 Sept. | Sunny | 20° /16° | 0 mm | 4.4 | |
| 13 Sept. | Patchy rain possible | 22° /18° | 2.3 mm | 3.9 | |
| 14 Sept. | Sunny | 21° /16° | 0 mm | 4.1 | |
| 15 Sept. | Sunny | 22° /16° | 0.1 mm | 6 | |
| 16 Sept. | Sunny | 18° /13° | 0 mm | 5 | |
| 17 Sept. | Overcast | 18° /12° | 0 mm | 4 | |
| 18 Sept. | Patchy rain possible | 18° /14° | 0.7 mm | 4 | |
| 19 Sept. | Light rain shower | 18° /15° | 8.8 mm | 4 | |
| 20 Sept. | Patchy rain possible | 17° /13° | 3.2 mm | 5 | |
| 21 Sept. | Patchy rain possible | 19° /15° | 5.4 mm | 5 | |
| 22 Sept. | Overcast | 17° /14° | 0 mm | 5 | |
| 23 Sept. | Sunny | 20° /17° | 0 mm | 5 | |
| 24 Sept. | Overcast | 21° /17° | 0 mm | 5 | |
| 25 Sept. | Overcast | 17° /13° | 3.1 mm | 4 | |
| 26 Sept. |  Patchy light rain with thunder | 16° /12° | 6.6 mm | 4 | |
| 27 Sept. | Patchy rain possible | 16° /12° | 3 mm | 4 | |
| 28 Sept. | Patchy rain possible | 16° /12° | 0.2 mm | 4 | |
| 29 Sept. | Overcast | 16° /11° | 1.8 mm | 4 | |
| 30 Sept. | Partly cloudy | 17° /12° | 4.4 mm | 5 | |
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Portsmouth in September - FAQ
What are the expected maximum and minimum temperatures in Portsmouth during September?
How much rainfall should be expected in Portsmouth during September?
What are the typical wind conditions in Portsmouth during September?
September rainfall patterns in Portsmouth
UV exposure in Portsmouth during September
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