Quincy Weather in September

What's the weather like in Quincy (Illinois) in September 2025?

The climate in Quincy during September can be summarized as warm and damp.

September is in the fall / autumn in Quincy and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 26°C (79°F), whilst at night 13°C (56°F) is normal.

Quincy weather averages (imperial / metric)
Daytime temperature 26°C 78.8°F
Nightly temperature 13.2°C 55.8°F
Average temperature 19.6°C 67.3°F
Daily sunshine 8.4 hrs
Avg rainfall 107 mm 4.2 ins
Rainy days 9 days
Sea temperature 20.4°C 68.7°F
Humidity 72%
Windspeed 14.8kph 9 mph

On average September is the 3rd wettest month of the year in Quincy with around 107mm 4.2 inches of rain making it a 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 8.4 hours of sunshine per day.

September temperatures in Quincy

Quincy average temperature in September

September rainfall

Quincy average rain in September

September hourly sunshine

Quincy 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 Quincy in September 2025.

Other monthly averages

Best places to visit in September

UV index Best time to go?

Beta

Current (hourly) weather 15 day forecast

Quincy weather stats

Quincy weather statistics
Hottest month: July 30.9°C 87.6°F
Driest month: January 36mm 1.4ins
Sunniest month: July 10.9hrs
Coldest month: January 0.3°C 32.5°F
Wettest month: July 117mm 4.6ins
Map showing location of Quincy (39.9356, -91.40987) Quincy map pin © Google

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