Hamilton Weather in September

The climate in Hamilton during September can be summarized as hot and a little damp.

September is in the fall / autumn in Hamilton and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 31°C (88°F), whilst at night 18°C (65°F) is normal.

On average September is the 3rd wettest month of the year in Hamilton with around 81mm 3.2 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 7 days, although this may vary considerably.

On the flip side this corresponds to an average of 8.7 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 Hamilton in September 2025.