Collinsville Weather in September

September in Collinsville averages 27°C (81°F) during the day and 15°C (59°F) at night. Quite a bit of rainfall is typical this month, with around 96 mm (3.8 in) on average. An umbrella is a good idea.

Rainfall in Collinsville in September

The climate data from previous years indicates about 9 days of rain, averaging 96 mm (3.8 in) for the month. Rainfall intensity is on the higher side this month. Expect more substantial showers rather than light, passing rain.

Temperature in Collinsville in September

Weather in Collinsville is at its perfect in September. Highs reach 27°C (81°F), while nights settle around 15°C (59°F). The days can feel warmer than the evenings, so packing for both parts of the day is a good idea. At 15°C (59°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 Collinsville in September

With approximately 235 hours of sunshine, the days are filled with clear skies. It makes it a perfect month for being outside.

If you're inclined towards comfortable temperatures and drier conditions, September is a good time to visit Collinsville.

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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 Collinsville's climate page.

Collinsville Temperature in September

Min Temperature 15°C (59°F)  

Max Temperature 27°C (81°F)  

Chance of Rain 30%  

Precipitation 96 mm (3.8 in)  

Rainy days 9 days  

Humidity 71% *  

Sunshine 235 hours *  

Percentage Sunshine 63% *  

* Data from: St. Louis, the United States of America (19 KM, 11 Miles).

What to Wear in Collinsville in September

Warm but pleasant conditions in Collinsville in September. Focus on lightweight, maybe with natural fabrics, cotton blend shirts, comfortable shorts, and breathable footwear. A light cover-up for sun protection is smart too. Expect heavy rainfall, so bring good rain protection and waterproof bags. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.

What To Do in Collinsville in September

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

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 Collinsville's climate page.

More climate data for Collinsville

Temperature Rainfall Sunshine Humidity

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