Saint Charles Weather in September

September in Saint Charles sees daytime temperatures around 24°C (75°F) and lows of 12°C (54°F) at night. With around 94 mm (3.7 in) of rainfall expected, it's worth packing a rain jacket.

Rainfall in Saint Charles in September

Historically, September sees about 9 days of rain, with a monthly average of 94 mm (3.7 in). The rain this month tends to fall in heavier spells rather than light drizzle. When it rains, showers can be significant.

Temperature in Saint Charles in September

The temperature in Saint Charles in September is perfect. Daytime highs reach 24°C (75°F), with nights dropping to 12°C (54°F). The days can feel warmer than the evenings, so packing for both parts of the day is a good idea. At 12°C (54°F) overnight, it can feel quite a bit cooler after dark. Worth packing something warmer for evenings, but the cooler temperatures are ideal for sleeping.

Sunshine in Saint Charles in September

The month enjoys around 226 hours of sunshine, creating mostly sunny days with good weather conditions.

If you're a fan of comfortable temperatures and drier conditions, September is a great time to visit.

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• January
• February
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• May
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• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Saint Charles's climate page.

Saint Charles Temperature in September

Min Temperature 12°C (54°F)  

Max Temperature 24°C (75°F)  

Chance of Rain 30%  

Precipitation 94 mm (3.7 in)  

Rainy days 9 days  

Humidity 71% *  

Sunshine 226 hours *  

Percentage Sunshine 60% *  

* Data from: Chicago, the United States of America (34 KM, 21 Miles).

What to Wear in Saint Charles in September

Pleasant temperatures in September mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Prepare for significant rainfall with proper waterproof clothing and shoes. You'll definitely want to pack sunglasses and sunscreen. There will be plenty of bright sunshine this month.

What To Do in Saint Charles in September

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

Swimming

9/10

Cycling

9/10

Walking

9/10

Barbeque

8/10

Camping

8/10

Outdoor sports

9/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Saint Charles's climate page.

More climate data for Saint Charles

Temperature Rainfall Sunshine Humidity

See the full Saint Charles climate overview or explore weather in the United States of America.