Fairfax Weather in August

The climate in Fairfax during August can be summarized as hot, humid and a little damp.

August is in the summer in Fairfax and is typically the 2nd warmest month of the year. Daytime maximum temperatures average around a muggy 30°C (86°F), whilst at night 19°C (65°F) is normal.

On average August is the wettest month of the year in Fairfax with around 100mm 3.9 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 10 days, although this may vary considerably.

On the flip side this corresponds to an average of 9 hours of sunshine per day.

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 Fairfax in August 2025.