Phoenix Weather in September

What's the weather like in Phoenix (Illinois) in September 2025?

The climate in Phoenix during September can be summarized as warm and a little damp.

September is in the fall / autumn in Phoenix and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 24°C (75°F), whilst at night 12°C (54°F) is normal.

Phoenix weather averages (imperial / metric)
Daytime temperature 24°C 75.2°F
Nightly temperature 12°C 53.6°F
Average temperature 18°C 64.4°F
Daily sunshine 8.3 hrs
Avg rainfall 91 mm 3.6 ins
Rainy days 9 days
Sea temperature 19.7°C 67.5°F
Humidity 72%
Windspeed 15.1kph 9 mph

On average September is the 5th wettest month of the year in Phoenix with around 91mm 3.6 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 9 days, although this may vary considerably.

On the flip side this corresponds to an average of 8.3 hours of sunshine per day.

September temperatures in Phoenix

Phoenix average temperature in September

September rainfall

Phoenix average rain in September

September hourly sunshine

Phoenix 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 Phoenix in September 2025.