This reference page collects chicago climate: monthly averages in one place: annual mean temperature 9.8 C; warmest month Aug (22.6 C); coldest month Jan (-2.5 C); wettest month May (3.79 mm/day). Figures are refreshed automatically by a scheduled build and cached locally so the page keeps its values even when the upstream API is temporarily unavailable. Use the table below for exact numbers, or the related pages for the same dataset for neighbouring periods and locations.
Annual mean temperature 9.8 C
Warmest month Aug (22.6 C)
Coldest month Jan (-2.5 C)
Wettest month May (3.79 mm/day)
All-time record high 34.7 C
All-time record low -24.8 C
Annual precipitation 982 mm / year
Coordinates 41.8781, -87.6298
Population 2,700,000
Average monthly temperature and rainfall in Chicago
Month
Mean temp (C)
Rain (mm/day)
Record high (C)
Record low (C)
Jan
-2.5
1.54
11.8
-24.8
Feb
-2.3
1.90
13.9
-19.4
Mar
2.0
2.00
20.9
-17.3
Apr
6.9
3.15
22.9
-4.4
May
11.8
3.79
29.0
0.8
Jun
18.1
3.41
30.7
3.7
Jul
22.5
3.07
34.7
12.2
Aug
22.6
3.40
32.4
13.0
Sep
19.1
2.86
30.7
8.0
Oct
12.3
3.18
26.2
0.1
Nov
6.0
2.03
19.8
-8.1
Dec
0.5
1.88
16.4
-18.6
What the Chicago climate table shows
Values are multi-decadal climatological averages for the 41.8781, -87.6298 grid cell, not a single year. Rain is the daily mean, so a value of 2.00 mm/day is about 60 mm across a 30-day month. Averages smooth over extremes, so use them for planning rather than for what to pack for next Tuesday.
Frequently asked questions
Where does the data on chicago climate: monthly averages come from?
From a public open API that is queried automatically and cached after every successful run.
How often is chicago climate: monthly averages updated?
The build runs on a schedule, so values refresh at least daily and old pages stay live.