Cities in Illinois — climate month by month
Compare 3 cities in Illinois, United States of America, across the year.
← Back to Illinois year-round average
| City | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chicago | -5.1°C22.8°F 46 mm1.8″ | -2.3°C27.9°F 40 mm1.6″ | 3.1°C37.6°F 68 mm2.7″ | 9.2°C48.6°F 97 mm3.8″ | 15.3°C59.5°F 93 mm3.7″ | 20.9°C69.6°F 103 mm4.1″ | 23.5°C74.3°F 96 mm3.8″ | 22.6°C72.7°F 102 mm4″ | 18.5°C65.3°F 91 mm3.6″ | 11.8°C53.2°F 71 mm2.8″ | 4.6°C40.3°F 81 mm3.2″ | -2°C28.4°F 65 mm2.6″ |
| Joliet | -5.5°C22.1°F 38 mm1.5″ | -2.5°C27.5°F 36 mm1.4″ | 3.6°C38.5°F 69 mm2.7″ | 9.8°C49.6°F 98 mm3.9″ | 16.1°C61°F 98 mm3.9″ | 21.5°C70.7°F 104 mm4.1″ | 23.9°C75°F 101 mm4″ | 22.8°C73°F 96 mm3.8″ | 18.6°C65.5°F 94 mm3.7″ | 11.9°C53.4°F 67 mm2.6″ | 4.6°C40.3°F 74 mm2.9″ | -2.1°C28.2°F 62 mm2.4″ |
| Springfield | -3.6°C25.5°F 42 mm1.7″ | -0.7°C30.7°F 46 mm1.8″ | 5.9°C42.6°F 81 mm3.2″ | 12°C53.6°F 92 mm3.6″ | 18°C64.4°F 106 mm4.2″ | 23.1°C73.6°F 98 mm3.9″ | 25.3°C77.5°F 92 mm3.6″ | 24°C75.2°F 87 mm3.4″ | 19.9°C67.8°F 80 mm3.1″ | 13.4°C56.1°F 67 mm2.6″ | 6.1°C43°F 74 mm2.9″ | -0.4°C31.3°F 66 mm2.6″ |
On mobile, scroll the table horizontally to see all months. Click a city name for its full year-round view.
Frequently asked questions
Which city in Illinois has the least rain?
Springfield is the driest city in Illinois, with approximately 931 mm / 36.7 in of average annual rainfall.
Which city in Illinois is warmest in July?
Springfield is the warmest city in Illinois in July, with an average temperature of 25.3°C / 77.5°F.
Which city in Illinois is warmest in January?
Springfield is the warmest city in Illinois in January, with an average temperature of -3.6°C / 25.5°F.
Which city in Illinois has the mildest year-round climate?
Springfield has the highest annual average temperature in Illinois at 11.9°C / 53.4°F, while Chicago has the lowest at 10°C / 50°F.
Which city in Illinois has the most sunny months?
Springfield matches our sunny profiles (warm/mild with limited rain) for 0 months of the year — the most of any city in Illinois.