Guerneville Weather in August

What's the weather like in Guerneville (California) in August 2025?

The climate in Guerneville during August can be summarized as warm and very dry.

August is in the summer in Guerneville and is typically the 2nd warmest month of the year. Daytime maximum temperatures average around a comfortable 29°C (85°F), whilst at night 11°C (53°F) is normal.

Guerneville weather averages (imperial / metric)
Daytime temperature 29.4°C 84.9°F
Nightly temperature 11.4°C 52.5°F
Average temperature 20.4°C 68.7°F
Daily sunshine 10.7 hrs
Avg rainfall 4 mm 0.2 ins
Rainy days 1 days
Sea temperature 14°C 57.2°F
Humidity 69%
Windspeed 16.9kph 11 mph

On average August is the 2nd driest month of the year in Guerneville with around 4mm 0.2 inches of rain making it a very dry time to visit.

On the flip side this corresponds to an average of 10.7 hours of sunshine per day.

August temperatures in Guerneville

Guerneville average temperature in August

August rainfall

Guerneville average rain in August

August hourly sunshine

Guerneville average rain in August

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 Guerneville in August 2025.

Other monthly averages

Best places to visit in August

UV index Best time to go?

Beta

Current (hourly) weather 15 day forecast

Guerneville weather stats

Guerneville weather statistics
Hottest month: July 29.3°C 84.7°F
Driest month: July 2mm 0.1ins
Sunniest month: April 10.9hrs
Coldest month: January 13.3°C 55.9°F
Wettest month: January 234mm 9.2ins
Map showing location of Guerneville (38.50186, -122.99611) Guerneville map pin © Google

Locations nearby

Top United States locations