Mahwah Weather in September

The climate in Mahwah during September can be summarized as very hot and damp.

September is in the fall / autumn in Mahwah and is typically the 6th warmest month of the year. Daytime maximum temperatures average around a warm 34°C (93°F), whilst at night 24°C (75°F) is normal.

On average September is the 3rd wettest month of the year in Mahwah with around 116mm 4.6 inches of rain making it a damp time to visit. This rainfall is typically spread over 4 days, although this may vary considerably.

On the flip side this corresponds to an average of 7.7 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 Mahwah in September 2025.