Romeoville Weather in September

During September, Romeoville experiences high daytime temperatures of 25°C (77°F) and cooler nights around 13°C (55°F). Expect quite a bit of rainfall. Around 85 mm (3.3 in) is typical.

Rainfall in Romeoville in September

Typically, about 9 days will experience rainfall, with an average of 85 mm (3.3 in) for the month. Rainfall intensity is on the higher side this month. Expect more substantial showers rather than light, passing rain.

Temperature in Romeoville in September

Romeoville in September is worth a visit. The temperature is perfect, with 25°C (77°F) during the day and 13°C (55°F) at night. The days can feel warmer than the evenings, so packing for both parts of the day is a good idea. Nights cool down to 13°C (55°F), so a light jacket or extra layer is useful once the sun goes down. On the plus side, the cooler nights make for comfortable sleeping conditions.

Sunshine in Romeoville in September

Expect a lot of sunshine this month, with about 226 hours of sun. These sunny conditions add to the overall experience.

Our weather planner can help you find worldwide destinations with pleasant weather during this period. September typically offers the best weather for Romeoville.

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

Romeoville Temperature in September

Min Temperature 13°C (55°F)  

Max Temperature 25°C (77°F)  

Chance of Rain 30%  

Precipitation 85 mm (3.3 in)  

Rainy days 9 days  

Humidity 71% *  

Sunshine 226 hours *  

Percentage Sunshine 60% *  

* Data from: Chicago, the United States of America (40 KM, 25 Miles).

What to Wear in Romeoville 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. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.

What To Do in Romeoville 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 Romeoville's climate page.

More climate data for Romeoville

Temperature Rainfall Sunshine Humidity

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