Decatur Weather in September

What's the weather like in Decatur (Illinois) in September 2024?

The climate in Decatur during September can be summarized as warm and a little damp.

September is in the fall / autumn in Decatur and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 26°C (79°F), whilst at night 13°C (55°F) is normal.

Decatur weather averages (imperial / metric)
Daytime temperature 26.3°C 79.3°F
Nightly temperature 12.7°C 54.9°F
Average temperature 19.5°C 67.1°F
Daily sunshine 8.7 hrs
Avg rainfall 81 mm 3.2 ins
Rainy days 9 days
Sea temperature 20.8°C 69.4°F
Humidity 72%
Windspeed 14kph 9 mph

On average September is the 6th wettest month of the year in Decatur with around 81mm 3.2 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 9 days, although this may vary considerably.

On the flip side this corresponds to an average of 8.7 hours of sunshine per day.

September temperatures in Decatur

Decatur average temperature in September

September rainfall

Decatur average rain in September

September hourly sunshine

Decatur average rain in September

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 Decatur in September 2024.