Menlo Park Weather in September

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

The climate in Menlo Park during September can be summarized as mild and very dry.

September is in the fall / autumn in Menlo Park and is typically the 2nd warmest month of the year. Daytime maximum temperatures average around a comfortable 24°C (75°F), whilst at night 12°C (53°F) is normal.

Menlo Park weather averages (imperial / metric)
Daytime temperature 23.8°C 74.8°F
Nightly temperature 11.9°C 53.3°F
Average temperature 17.8°C 64°F
Daily sunshine 10 hrs
Avg rainfall 7 mm 0.3 ins
Rainy days 2 days
Sea temperature 14.4°C 57.9°F
Humidity 70%
Windspeed 16.2kph 10 mph

On average September is the 4th driest month of the year in Menlo Park 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 10 hours of sunshine per day.

September temperatures in Menlo Park

Menlo Park average temperature in September

September rainfall

Menlo Park average rain in September

September hourly sunshine

Menlo Park 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 Menlo Park in September 2025.