Chicago in September
In September, Chicago has 81.0 mm (3.19 in) of rain, a daily high of 24.2 °C (75.6 °F) and a daily low of 13.9 °C (57.0 °F), as 1991-2020 means; figures in brackets are converted.
Last updated : what the month is like; shorter source notes.
Best time to visit Chicago: September meets our rule. Expect days that shorten by 1 h 20 min.
What September is like in Chicago
- Folk dancers and mariachi bands march through Little Village in mid-September. Thousands come out for the Mexican Independence Day Parade. Source: Choose Chicago (official tourism site), checked .
- Jazz plays at the Chicago Cultural Center and in Millennium Park for the Chicago Jazz Festival. It is a Labor Day weekend tradition in early September. Source: City of Chicago (Department of Cultural Affairs and Special Events), checked .
- From September, anglers on the lakefront and in the harbors fish for Chinook and coho salmon. From October, they may snag them in the Lincoln Park Lagoon. Source: Chicago Park District, checked .
Key figures
Weather in September, 1991-2020 means
- Daily high
- 24.2 °C (75.6 °F)
- Daily low
- 13.9 °C (57.0 °F)
- Rain
- 81.0 mm (3.19 in) in the month
- Sunshine
- no data
U.S. Climate Normals 1991-2020, NOAA. Checked .
Measured at Chicago O'Hare International Airport, 28 km north-west of the city centre point.
How we define and convert these figures
Notes. Daily high and low: changed: source gives °F; converted to °C, rounded to 0.1. Rain: changed: source gives inches; converted to mm (x 25.4), rounded to 0.1. Sunshine: the NOAA U.S. monthly normals have no sunshine measure.
Daylight on 15 September 2026
- Sunrise
- 06:31 local time
- Sunset
- 19:00 local time
- Day length
- 12 h 29 min
Day length 1-30 September: 13 h 07 min to 11 h 47 min, -1 h 20 min.
Source: NOAA Solar Calculator equations, checked .
Month by month
Each month: daily high in °C, then rain in mm, 1991-2020 means.
NOAA U.S. Climate Normals 1991-2020, as above, checked .
This month against the year
| Measure | September | Rank |
|---|---|---|
| Daily high | 24.2 °C | 4th warmest |
| Daily low | 13.9 °C | 4th warmest |
| Rain | 81.0 mm | 6th driest |
| Sunshine | no data | no data |
| Day length | 12 h 29 min | 6th longest |
Equal values share a rank. How we rank months
NOAA U.S. Climate Normals 1991-2020, as above, checked .
Day length: NOAA solar equations, checked .
Public holidays this month
| Date | Holiday |
|---|---|
| Monday | Labor Day opm.gov |
| Date | Holiday |
|---|---|
| Monday | Labor Day opm.gov |
Typed from the official list and re-checked, .
Source: Official public holiday list (cms.illinois.gov), checked .
Same month in 20 cities
Chicago is warmer than 8 of our 20 cities in September by mean daily high. How we rank cities
Closest high and low in September: New York (1.7 °C apart), Paris (1.8), Madrid (2.2).
| City | Gap from Chicago, °C | High, °C | Low, °C | Rain, mm | Sunshine, hours |
|---|---|---|---|---|---|
| Chicago (this page) | — | 24.2 | 13.9 | 81.0 | no data |
| New York (closest) | 1.7 | 24.6 | 16.8 | 109.5 | no data |
| Paris (closest) | 1.8 | 21.5 | 13.0 | 44.7 | 174.0 |
| Madrid (closest) | 2.2 | 26.9 | 15.5 | 23.6 | no data |
| Rome | 2.3 | 26.7 | 16.0 | no data | no data |
| Vienna | 2.5 | 21.1 | 12.0 | 64.1 | 191.7 |
| London | 2.8 | 20.2 | 12.3 | 49.8 | no data |
| Barcelona | 3.7 | 26.7 | 18.8 | 86.1 | 202.9 |
| Berlin | 3.7 | 19.9 | 10.9 | 46.6 | 166.6 |
| Buenos Aires | 3.9 | 19.7 | 10.6 | 80.6 | 178.9 |
| Amsterdam | 4.0 | 19.2 | 11.0 | 84.4 | 154.2 |
| Los Angeles | 4.1 | 28.3 | 17.9 | 3.3 | no data |
| Munich | 4.1 | 19.6 | 10.4 | 78.1 | 169.7 |
| Prague | 4.1 | 20.1 | 9.9 | 41.8 | 164.6 |
| Tokyo | 4.9 | 27.5 | 20.3 | 224.9 | 126.7 |
| Seville | 5.6 | 31.1 | 18.2 | 33.1 | 278.4 |
| Hiroshima | 6.1 | 29.1 | 21.1 | 162.7 | 167.3 |
| Osaka | 6.7 | 29.5 | 21.9 | 152.8 | 161.6 |
| Hong Kong | 9.3 | 30.5 | 26.1 | 321.4 | 174.4 |
| Singapore | 9.4 | 31.6 | 25.2 | 124.9 | no data |
Sources (1991-2020): WMO climate normals and NOAA U.S. Climate Normals, checked , ; Hong Kong: our 1991-2020 mean of the Hong Kong Observatory daily climate series on DATA.GOV.HK; Singapore: our 1991-2020 mean of the National Environment Agency monthly climate series on data.gov.sg; both checked . Each city's page names its station. All sources in full on Methodology.
Hong Kong figures: The Government of the Hong Kong Special Administrative Region and the Hong Kong Observatory own the intellectual property rights in the data; attribution to them and DATA.GOV.HK. Licence: Terms and Conditions of Use of DATA.GOV.HK, version 1.2.
Singapore figures: Contains information from the National Environment Agency on data.gov.sg, made available under the terms of the Singapore Open Data Licence version 1.0 (https://data.gov.sg/open-data-licence). The Agency does not endorse our means.
Sources
- Attribution: Palecki, Michael; Durre, Imke; Applequist, Scott; Arguez, Anthony; Lawrimore, Jay (2021). U.S. Climate Normals 2020: U.S. Monthly Climate Normals (1991-2020). Station files named in each record. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/wck8-er13. Accessed on the check date shown. Licence: No licence stated; citation requested. Checked .
- NOAA Solar Calculator equations, computed locally, NOAA Global Monitoring Laboratory (method); City by Month (computation). Attribution: Computed with the NOAA Solar Calculator method (no NOAA endorsement implied). Licence: Method, not data. Checked .
Official sources
Cite this page: City by Month. "Chicago in September: weather, daylight, holidays". https://citybymonth.com/cities/united-states/chicago/september/. Last updated 5 November 2026.