Joliet, IL Weather & Climate Normals
Joliet's real weather, in one number
Joliet, IL scores 46/100 on this site's reading of NOAA's own 30-year normals: strongly seasonal. Comfortable weather is limited to a shorter window; summers, winters, or precipitation swing wide. 5 of the year's 12 months average between 55 and 75°F, the range this site counts as mild.
Joliet's hottest and coldest months
Joliet's hottest month is Jul, averaging 74°F; its coldest is Jan, averaging 24°F, a 50°F swing across the year, one of the widest gaps in this dataset.
Rain and snow in Joliet
Joliet averages 38.03in of precipitation a year across roughly 123 days with measurable rain or snow, and 16.9in of snow a year.
Where Joliet ranks
Joliet ranks 2903 of 4876 US cities in this dataset for comfort score, and 94 of 330 within IL. About 151,837 people live there.
If you need tomorrow's forecast, not the 30-year average
Everything above is a 30-year average from JOLIET BRANDON RD DAM, IL US, 2.5 miles from Joliet, not a prediction for any specific day.
More on how this is worked out
How the comfort score is calculated · Why some cities show no snow or rain figure