The climate in Trosa during September can be summarized as mild and reasonably dry.
September is in the fall / autumn in Trosa and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a cool 15°C (60°F), whilst at night 8°C (47°F) is normal.
| Daytime temperature | 15.4°C 59.7°F |
|---|---|
| Nightly temperature | 8.4°C 47.1°F |
| Average temperature | 11.9°C 53.4°F |
| Daily sunshine | 5 hrs |
| Avg rainfall | 49 mm 1.9 ins |
| Rainy days | 14 days |
| Sea temperature | 14.2°C 57.6°F |
| Humidity | 80% |
| Windspeed | 15.1kph 9 mph |
On average September is the 4th wettest month of the year in Trosa with around 49mm 1.9 inches of rain making it a reasonably dry time to visit. This rainfall is typically spread over 14 days, although this may vary considerably.
On the flip side this corresponds to an average of 5 hours of sunshine per day.
The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Trosa in September 2025.
Best places to visit in September
| Hottest month: | July | 21.3°C 70.3°F |
|---|---|---|
| Driest month: | March | 23mm 0.9ins |
| Sunniest month: | June | 9.8hrs |
| Coldest month: | February | -0.5°C 31.1°F |
| Wettest month: | July | 57mm 2.2ins |