The climate in Colonial Beach during September can be summarized as warm, humid and a little damp.
September is in the fall / autumn in Colonial Beach and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a muggy 27°C (80°F), whilst at night 16°C (60°F) is normal.
| Daytime temperature | 26.6°C 79.9°F | 
|---|---|
| Nightly temperature | 15.6°C 60.1°F | 
| Average temperature | 21.1°C 70°F | 
| Daily sunshine | 8.2 hrs | 
| Avg rainfall | 88 mm 3.4 ins | 
| Rainy days | 7 days | 
| Sea temperature | 21.7°C 71.1°F | 
| Humidity | 74% | 
| Windspeed | 12.6kph 8 mph | 
On average September is the 5th wettest month of the year in Colonial Beach with around 88mm 3.4 inches of rain making it a a little damp 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 8.2 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 Colonial Beach in September 2025.
Best places to visit in September
| Hottest month: | July | 30.6°C 87.1°F | 
|---|---|---|
| Driest month: | February | 75mm 3ins | 
| Sunniest month: | June | 10.3hrs | 
| Coldest month: | January | 6.3°C 43.3°F | 
| Wettest month: | August | 105mm 4.1ins |