Arcata Weather in September

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

The climate in Arcata during September can be summarized as mild and dry.

September is in the fall / autumn in Arcata and is typically the 3rd warmest month of the year. Daytime maximum temperatures average around 20°C (67°F), whilst at night 10°C (51°F) is normal.

Arcata weather averages (imperial / metric)
Daytime temperature 19.7°C 67.4°F
Nightly temperature 10.4°C 50.6°F
Average temperature 15°C 59°F
Daily sunshine 8.5 hrs
Avg rainfall 26 mm 1 ins
Rainy days 4 days
Sea temperature 13.9°C 57°F
Humidity 67%
Windspeed 12.2kph 8 mph

On average September is the 4th driest month of the year in Arcata with around 26mm 1 inches of rain making it a dry time to visit. This rainfall is typically spread over 4 days, although this may vary considerably.

On the flip side this corresponds to an average of 8.5 hours of sunshine per day.

September temperatures in Arcata

Arcata average temperature in September

September rainfall

Arcata average rain in September

September hourly sunshine

Arcata 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 Arcata 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

Arcata weather stats

Arcata weather statistics
Hottest month: August 19.6°C 67.3°F
Driest month: July 4mm 0.2ins
Sunniest month: July 10.3hrs
Coldest month: January 11.9°C 53.4°F
Wettest month: December 192mm 7.6ins
Map showing location of Arcata (40.86652, -124.08284) Arcata map pin © Google

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