Chicago weather in May
In May, Chicago has an average high of 15 °C59 °F and an average low of 9 °C47 °F, with about 117 mm4.6 in of precipitation. It is the 6th warmest month of the year and the wettest.
How May compares with other months
Compared with April, May is 4.9 °C8.9 °F warmer on average and wetter by 23 mm0.9 in. Compared with June, May is 6.3 °C11.3 °F cooler on average and wetter by 15 mm0.6 in. Daylight lasts about 14.5 hours around the middle of the month. Average relative humidity is 83% and the average cloud amount 64%.
Is May a good time to visit Chicago?
May is not among the most comfortable months by our comfort score: it is cool (average high 15 °C59 °F) and it is fairly wet (117 mm4.6 in). The most comfortable months in Chicago are June and July and September.
What to wear in May
For Chicago in May, pack long sleeves, a sweater and a medium jacket and an umbrella or light rain jacket.
May in nearby places
| Place | High °C°F | Low °C°F | Precip. mmin |
|---|---|---|---|
| Chicago | 1559 | 947 | 1174.6 |
| Joliet | 2272 | 1050 | 1174.6 |
| Elgin | 2169 | 948 | 1204.7 |
| Aurora | 2170 | 948 | 1204.7 |
| South Bend | 2170 | 1050 | 1124.4 |
| Rockford | 2170 | 948 | 1084.3 |
| Milwaukee | 1966 | 846 | 1094.3 |
| Madison | 2068 | 847 | 1094.3 |
| Grand Rapids | 2068 | 847 | 1044.1 |
Nearby places that are more than 1 °C1.8 °F warmer in May: Joliet, Elgin, Aurora and South Bend.
Other months in Chicago
- January0 °C32 °F / −5 °C23 °F
- February0 °C33 °F / −5 °C23 °F
- March5 °C41 °F / −1 °C31 °F
- April10 °C50 °F / 4 °C39 °F
- May15 °C59 °F / 9 °C47 °F
- June21 °C70 °F / 15 °C59 °F
- July25 °C77 °F / 20 °C68 °F
- August25 °C77 °F / 20 °C68 °F
- September22 °C71 °F / 16 °C62 °F
- October15 °C59 °F / 10 °C49 °F
- November9 °C47 °F / 3 °C38 °F
- December3 °C37 °F / −2 °C29 °F
Frequently asked questions
How warm is Chicago in May?
In May the average high in Chicago is 15 °C (59 °F) and the average low is 9 °C (47 °F).
Does it rain a lot in Chicago in May?
On average about 117 mm (4.6 in) of precipitation falls in May; it ranks 1st of the 12 months.
Is May the warmest month in Chicago?
No. The warmest month in Chicago is July, with an average high of 25 °C (77 °F). The coldest month is February, with an average low of -5 °C (23 °F).
How long is the day in Chicago in May?
In the middle of May the day in Chicago lasts about 14.5 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Chicago in May?
The average relative humidity in May is about 83%. This is a long-term average for the whole day.
How cloudy is Chicago in May?
On average about 64% of the sky is covered by cloud in May. This is the mean cloud amount from satellite data, not the number of sunny days.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.