Diamond Bar Weather in September

What's the weather like in Diamond Bar (California) in September 2024?

The climate in Diamond Bar during September can be summarized as warm and dry.

September is in the fall / autumn in Diamond Bar and is typically the 3rd warmest month of the year. Daytime maximum temperatures average around a comfortable 30°C (87°F), whilst at night 14°C (58°F) is normal.

Diamond Bar weather averages (imperial / metric)
Daytime temperature 30.4°C 86.7°F
Nightly temperature 14.4°C 57.9°F
Average temperature 22.4°C 72.3°F
Daily sunshine 10.2 hrs
Avg rainfall 10 mm 0.4 ins
Rainy days 2 days
Sea temperature 19.6°C 67.3°F
Humidity 63%
Windspeed 12.6kph 8 mph

On average September is the 6th driest month of the year in Diamond Bar 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 10.2 hours of sunshine per day.

September temperatures in Diamond Bar

Diamond Bar average temperature in September

September rainfall

Diamond Bar average rain in September

September hourly sunshine

Diamond Bar 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 Diamond Bar in September 2024.