Crystal Lake Weather in September

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

The climate in Crystal Lake during September can be summarized as mild and a little damp.

September is in the fall / autumn in Crystal Lake and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 23°C (74°F), whilst at night 11°C (52°F) is normal.

Crystal Lake weather averages (imperial / metric)
Daytime temperature 23.3°C 73.9°F
Nightly temperature 11.1°C 52°F
Average temperature 17.2°C 63°F
Daily sunshine 8 hrs
Avg rainfall 92 mm 3.6 ins
Rainy days 10 days
Sea temperature 19.2°C 66.5°F
Humidity 73%
Windspeed 15.5kph 10 mph

On average September is the 5th wettest month of the year in Crystal Lake with around 92mm 3.6 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 10 days, although this may vary considerably.

On the flip side this corresponds to an average of 8 hours of sunshine per day.

September temperatures in Crystal Lake

Crystal Lake average temperature in September

September rainfall

Crystal Lake average rain in September

September hourly sunshine

Crystal Lake 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 Crystal Lake in September 2024.

Other monthly averages

Best places to visit in September

UV index Best time to go?

Crystal Lake weather stats

Crystal Lake weather statistics
Hottest month: July 28.2°C 82.8°F
Driest month: February 32mm 1.3ins
Sunniest month: July 10.9hrs
Coldest month: January -2.7°C 27.1°F
Wettest month: June 102mm 4ins
Map showing location of Crystal Lake (42.24113, -88.3162) Crystal Lake map pin © Google

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