Alton weather in September (Illinois, United States of America)

What kind of temperatures can you expect in Alton during September? Wondering about the weather this month? Our guide has all the details you need.

Temperatures

The weather in Alton during September is usually perfect, offering high temperatures and moderate rainfall. Expect temperatures to climb to 27°C during the day, with nighttime readings dropping to 15°C.

Precipitation

Alton in September usually receives moderate rainfall, averaging around 92 mm for the month. According to historical climate patterns, there are usually around 9 days days of rain.

Average sunshine

There are approximately 235 hours of sunshine this month, meaning plenty of sunny days and a vibrant atmosphere.

So this is a great month to visit if you prefer dry days with pleasant temperatures. September and October typically offer the most optimal weather. In contrast, January, February and December tend to have less optimal conditions.

For an in-depth look at the yearly conditions, visit our specialized Alton climate page with graphs.

 

Alton, monthly averages in September

Min Temperature 15°C  

Max Temperature 27°C  

Chance of Rain 29%  

Precipitation 92 mm  

Rainy days 9 days  

Humidity 71% *  

Sunshine 235 hours *  

Percentage Sunshine 63% *  

Data from: St. Louis, the United States of America (29 KM, 18 Miles).

Where to go in the United States of America in September

Find out more about the weather in the United States of America and which places have the best travel conditions in this month.

Weather conditions Weather

Temperatures

Precipitation

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Legend perfect weather pleasant tolerable unpleasant poor

Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C and 29°C and not too much precipitation (less than 90 mm a month).

So, what should you wear in this month?

It's going to be warm! Consider airy clothing, t-shirts, and other summer clothes. Shorts for men made of cotton or linen are good options for staying cool. However, there's a good chance of rain, so bring a raincoat just in case.

What To Do

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

9/10

Cycling

7/10

Walking

7/10

Camping

8/10

Outdoor sports

7/10

Interested in more climate information?

This site provides you with all the information you need about the climate in Alton.

Our site offers climate and forecast data for every country in the world. Are you going to the United States of America? On this website you can find historical weather averages for many cities in the United States of America. Not sure yet where to go? We now have a tool which recommends destinations that suit your ideal travel conditions. Find out where to go with our weather planner.