Alton Weather in May

What's the weather like in Alton (Missouri) in May 2025?

The climate in Alton during May can be summarized as mild and damp.

May is in the spring in Alton and is typically the 5th warmest month of the year. Daytime maximum temperatures average around a comfortable 25°C (77°F), whilst at night 11°C (51°F) is normal.

Alton weather averages (imperial / metric)
Daytime temperature 25°C 77°F
Nightly temperature 10.6°C 51.1°F
Average temperature 17.8°C 64°F
Daily sunshine 10.4 hrs
Avg rainfall 118 mm 4.6 ins
Rainy days 11 days
Sea temperature 16.5°C 61.6°F
Humidity 69%
Windspeed 15.1kph 9 mph

On average May is the wettest month of the year in Alton with around 118mm 4.6 inches of rain making it a damp time to visit. This rainfall is typically spread over 11 days, although this may vary considerably.

On the flip side this corresponds to an average of 10.4 hours of sunshine per day.

May temperatures in Alton

Alton average temperature in May

May rainfall

Alton average rain in May

May hourly sunshine

Alton average rain in May

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 Alton in May 2025.

Other monthly averages

Best places to visit in May

UV index Best time to go?

Beta

Current (hourly) weather 15 day forecast

Alton weather stats

Alton weather statistics
Hottest month: July 32°C 89.6°F
Driest month: January 68mm 2.7ins
Sunniest month: July 11hrs
Coldest month: January 5.4°C 41.7°F
Wettest month: May 118mm 4.6ins
Map showing location of Alton (36.69423, -91.3993) Alton map pin © Google

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