Fullerton Weather in October

What's the weather like in Fullerton (California) in October 2025?

The climate in Fullerton during October can be summarized as warm and very dry.

October is in the fall / autumn in Fullerton and is typically the 5th warmest month of the year. Daytime maximum temperatures average around a comfortable 26°C (80°F), whilst at night 13°C (55°F) is normal.

Fullerton weather averages (imperial / metric)
Daytime temperature 26.4°C 79.5°F
Nightly temperature 12.6°C 54.7°F
Average temperature 19.5°C 67.1°F
Daily sunshine 8.9 hrs
Avg rainfall 7 mm 0.3 ins
Rainy days 2 days
Sea temperature 19.3°C 66.7°F
Humidity 66%
Windspeed 11.2kph 7 mph

On average October is the 5th driest month of the year in Fullerton with around 7mm 0.3 inches of rain making it a very dry time to visit.

On the flip side this corresponds to an average of 8.9 hours of sunshine per day.

October temperatures in Fullerton

Fullerton average temperature in October

October rainfall

Fullerton average rain in October

October hourly sunshine

Fullerton average rain in October

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 Fullerton in October 2025.

Other monthly averages

Best places to visit in October

UV index Best time to go?

Beta

Current (hourly) weather 15 day forecast

Fullerton weather stats

Fullerton weather statistics
Hottest month: August 29.8°C 85.6°F
Driest month: July 1mm 0ins
Sunniest month: August 11.7hrs
Coldest month: January 19.3°C 66.7°F
Wettest month: January 82mm 3.2ins
Map showing location of Fullerton (33.87029, -117.92534) Fullerton map pin © Google

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