Illinois · United States
Chicago in September
In September, Chicago averages a daytime high of 24 °C and a night-time low of 13 °C, with about 82 mm of rain over the month. Chicago has no month that is both mild and dry by the measure used here.
- Average high
- 24 °C
- Average low
- 13 °C
- Rain in the month
- 82 mm
- Daylight on 15 Sep
- 12 h 20 min
- Comfortable month
- No
- Places to stay
- 73
When to go
How September compares with the rest of the year in Chicago
September is the 4th warmest month in Chicago by average daytime high; across the year the highs run from 0 °C to 29 °C and the lows from -8 °C to 18 °C. By day, September is 4 °C cooler than August, and October is 7 °C cooler than September.
September brings 82 mm of rain, less than the monthly average of 82 mm (989 mm a year); it is the 7th wettest month.
On 15 September the sun is up for about 12 h 20 min, against 9 h 10 min at the shortest and 15 h 10 min at the longest point of the year (calculated from the latitude, sunrise to sunset).
| Month | High | Low | Rain | Comfortable |
|---|---|---|---|---|
| January | 0 °C | -8 °C | 57 mm | |
| February | 2 °C | -7 °C | 48 mm | |
| March | 9 °C | -1 °C | 64 mm | |
| April | 15 °C | 4 °C | 106 mm | |
| May | 22 °C | 10 °C | 104 mm | |
| June | 27 °C | 15 °C | 116 mm | |
| July | 29 °C | 18 °C | 102 mm | |
| August | 28 °C | 17 °C | 101 mm | |
| September | 24 °C | 13 °C | 82 mm | |
| October | 17 °C | 7 °C | 86 mm | |
| November | 9 °C | 0 °C | 68 mm | |
| December | 3 °C | -5 °C | 55 mm |
Comfortable means average daytime high between 18 °C and 29 °C and under 80 mm of rain in the month. Averages for 1991–2020 over the surrounding area, a grid square about 50 km across, so a coast or a nearby mountain can make the town itself warmer or cooler. Data: CRU TS v4.10, Climatic Research Unit, University of East Anglia (Open Database License).
When to go
Is September a good time to visit Chicago?
Not by the measure used here: about 82 mm of rain is 80 mm or more. No month in Chicago meets it.
The measure is about weather for a city stay only; it says nothing about events, school holidays or prices.
Public holidays in United States in September
Nationwide public holidays; shops and offices may close on these dates.
When to go
Destinations near Chicago that are comfortable in September
Within 300 km, nearest first, by the same measure.
Where to stay
Where to stay in Chicago
This guide lists 73 places to stay in Chicago, hotels recorded in Wikidata. By straight-line distance from the centre: under 1 km, 42; 1–3 km, 18; 3–10 km, 13.
Sources: climate from CRU TS v4.10 (Climatic Research Unit, University of East Anglia; Open Database License), 1991–2020 averages; day length calculated from the latitude; public holidays from python-holidays (MIT); places to stay from each operator's own public pages and Wikidata. How this guide is made.