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Chicago Weather in September

September in Chicago brings high temperatures, with daytime highs of 24°C (75°F) and nights around 14°C (57°F). Quite a bit of rainfall is expected, around 95 mm (3.7 in), so pack an umbrella.

Rainfall in Chicago in September

Analyzing past climate data, one can expect approximately 9 days of rain, averaging 95 mm (3.7 in). Individual showers can be quite heavy this month. A proper umbrella or rain jacket is worth having.

Temperature in Chicago in September

Chicago in September is worth a visit. The temperature is excellent, with 24°C (75°F) during the day and 14°C (57°F) at night. Conditions stay fairly consistent through the month, making it easier to plan what to wear. With lows of 14°C (57°F), nights are cool. If you're out after dark, an extra layer will keep you comfortable. The cooler air at night is also great for getting a good rest.

Sunshine in Chicago in September

Enjoy a sunny month with about 226 hours of sunshine, the clear skies make Chicago even more beautiful.

Wind Speed in Chicago in September

September sees wind speeds averaging 4 m/s (8 knots). You'll experience variable conditions with moderate winds that create small waves on water and keep branches moving. Conditions range from light winds to moderate breezes throughout the month.

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

Chicago Temperature in September

Min Temperature
14°C (57°F)
Max Temperature
24°C (75°F)
Chance of Rain
29%
Precipitation
95 mm (3.7 in)
Rainy days
9 days
Humidity
71%
Windspeed
4 m/s (8 knots)
Sunshine
226 hours
Percentage Sunshine
60%

Chicago Weather by Month

Pick a month to see the average temperature, rainfall and sunshine in Chicago - and find the best time to visit.

Daily Historical Temperatures

50-year average (1976-2025)

Based on our historical records, temperatures in Chicago typically drop from around 27°C (81°F) at the start of September to approximately 21°C (70°F) by the end. Nights are cool, with lows typically ranging from 11°C (52°F) to 17°C (63°F).

Average temperatures in September

Daily Historical Precipitation

50-year average (1976-2025)

Average daily rainfall for each day of the month based on long-term records.

Average precipitation in September

Historical weather records for Chicago in September

Browse day-by-day weather records for Chicago spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.

Chicago historical weather extremes in September

According to our 50 years of weather records for Chicago, the following extremes were recorded between 1976 and 2026.

  • The warmest day in September was on September 7, 1985, with a maximum of 36°C (97°F).
  • On September 27, 1984, Chicago saw its coldest September day with temperatures maxing out at 10°C (50°F).
  • The lowest overnight temperature recorded in September was -1°C (30°F) (September 23, 1995).

Best Places 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. See all of the United States of America in September →

perfect weather
pleasant
tolerable
unpleasant
poor

Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C (68°F) and 29°C (84°F) and not too much precipitation (less than 90 mm (3.5 in) a month).

What to Wear in Chicago 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. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.

What To Do in Chicago 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

Chicago 3-Day Forecast

Popular in September

Where to go in September - average daytime high across popular destinations.

Bucket list

Need travel inspiration? Check out our bucket list articles and be inspired.