Guerneville Weather in July

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

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

July is in the summer in Guerneville and is typically the warmest month of the year. Daytime maximum temperatures average around a comfortable 30°C (86°F), whilst at night 11°C (52°F) is normal.

Guerneville weather averages (imperial / metric)
Daytime temperature 29.8°C 85.6°F
Nightly temperature 11.3°C 52.3°F
Average temperature 20.5°C 68.9°F
Daily sunshine 11.8 hrs
Avg rainfall 2 mm 0.1 ins
Rainy days 1 days
Sea temperature 13.1°C 55.5°F
Humidity 67%
Windspeed 18kph 11 mph

On average July is the driest month of the year in Guerneville with around 2mm 0.1 inches of rain making it a very dry time to visit.

On the flip side this corresponds to an average of 11.8 hours of sunshine per day.

July temperatures in Guerneville

Guerneville average temperature in July

July rainfall

Guerneville average rain in July

July hourly sunshine

Guerneville average rain in July

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 July 2025.