Irvine Weather in September

What's the weather like in Irvine (California) in September 2025?

The climate in Irvine during September can be summarized as warm and very dry.

September is in the fall / autumn in Irvine and is typically the 3rd warmest month of the year. Daytime maximum temperatures average around a comfortable 28°C (82°F), whilst at night 15°C (58°F) is normal.

Irvine weather averages (imperial / metric)
Daytime temperature 28°C 82.3°F
Nightly temperature 14.7°C 58.4°F
Average temperature 21.3°C 70.3°F
Daily sunshine 9.9 hrs
Avg rainfall 6 mm 0.2 ins
Rainy days 2 days
Sea temperature 20.4°C 68.8°F
Humidity 67%
Windspeed 12.2kph 8 mph

On average September is the 5th driest month of the year in Irvine with around 6mm 0.2 inches of rain making it a very dry time to visit.

On the flip side this corresponds to an average of 9.9 hours of sunshine per day.

September temperatures in Irvine

Irvine average temperature in September

September rainfall

Irvine average rain in September

September hourly sunshine

Irvine 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 Irvine 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

Irvine weather stats

Irvine weather statistics
Hottest month: August 28.8°C 83.8°F
Driest month: July 1mm 0ins
Sunniest month: August 11.5hrs
Coldest month: January 18.6°C 65.5°F
Wettest month: January 75mm 3ins
Map showing location of Irvine (33.66946, -117.82311) Irvine map pin © Google

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