Ottawa Weather in September

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

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

September is in the fall / autumn in Ottawa and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 25°C (77°F), whilst at night 12°C (54°F) is normal.

Ottawa weather averages (imperial / metric)
Daytime temperature 24.9°C 76.7°F
Nightly temperature 12.2°C 53.9°F
Average temperature 18.5°C 65.3°F
Daily sunshine 8.3 hrs
Avg rainfall 92 mm 3.6 ins
Rainy days 9 days
Sea temperature 19.4°C 66.8°F
Humidity 73%
Windspeed 14.4kph 9 mph

On average September is the 2nd wettest month of the year in Ottawa with around 92mm 3.6 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 8.3 hours of sunshine per day.

September temperatures in Ottawa

Ottawa average temperature in September

September rainfall

Ottawa average rain in September

September hourly sunshine

Ottawa 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 Ottawa in September 2024.

Other monthly averages

Best places to visit in September

UV index Best time to go?

Beta

Current (hourly) weather 15 day forecast

Ottawa weather stats

Ottawa weather statistics
Hottest month: July 29.3°C 84.7°F
Driest month: February 29mm 1.1ins
Sunniest month: July 10.8hrs
Coldest month: January -1.7°C 28.9°F
Wettest month: June 100mm 3.9ins
Map showing location of Ottawa (41.34559, -88.84258) Ottawa map pin © Google

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