Rio Del Mar Weather in September

What's the weather like in Rio Del Mar (California) in September 2025?

The climate in Rio Del Mar during September can be summarized as mild and dry.

September is in the fall / autumn in Rio Del Mar and is typically the 2nd warmest month of the year. Daytime maximum temperatures average around a comfortable 25°C (77°F), whilst at night 11°C (51°F) is normal.

Rio Del Mar weather averages (imperial / metric)
Daytime temperature 25°C 76.9°F
Nightly temperature 10.5°C 50.8°F
Average temperature 17.7°C 63.9°F
Daily sunshine 10.3 hrs
Avg rainfall 10 mm 0.4 ins
Rainy days 2 days
Sea temperature 15.8°C 60.4°F
Humidity 69%
Windspeed 14.8kph 9 mph

On average September is the 5th driest month of the year in Rio Del Mar with around 10mm 0.4 inches of rain making it a dry time to visit. This rainfall is typically spread over 2 days, although this may vary considerably.

On the flip side this corresponds to an average of 10.3 hours of sunshine per day.

September temperatures in Rio Del Mar

Rio Del Mar average temperature in September

September rainfall

Rio Del Mar average rain in September

September hourly sunshine

Rio Del Mar 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 Rio Del Mar 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

Rio Del Mar weather stats

Rio Del Mar weather statistics
Hottest month: August 24.5°C 76.1°F
Driest month: July 2mm 0.1ins
Sunniest month: April 11.2hrs
Coldest month: December 14.7°C 58.5°F
Wettest month: January 135mm 5.3ins
Map showing location of Rio Del Mar (36.96828, -121.90023) Rio Del Mar map pin © Google

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