The climate in Williston during September can be summarized as mild and reasonably dry.
September is in the fall / autumn in Williston and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 21°C (70°F), whilst at night 6°C (42°F) is normal.
| Daytime temperature | 21.3°C 70.3°F |
|---|---|
| Nightly temperature | 5.7°C 42.3°F |
| Average temperature | 13.5°C 56.3°F |
| Daily sunshine | 8.9 hrs |
| Avg rainfall | 36 mm 1.4 ins |
| Rainy days | 7 days |
| Sea temperature | 13.4°C 56.2°F |
| Humidity | 61% |
| Windspeed | 17.3kph 11 mph |
On average September is the 5th wettest month of the year in Williston with around 36mm 1.4 inches of rain making it a reasonably dry time to visit. This rainfall is typically spread over 7 days, although this may vary considerably.
On the flip side this corresponds to an average of 8.9 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 Williston in September 2025.
Best places to visit in September
| Hottest month: | July | 29°C 84.2°F |
|---|---|---|
| Driest month: | February | 10mm 0.4ins |
| Sunniest month: | July | 12.7hrs |
| Coldest month: | January | -7.1°C 19.2°F |
| Wettest month: | June | 72mm 2.8ins |