Illinois Weather, climate and geography

Weather & climate

Best time to visit

Wide variation between hot summers and freezing winters, especially in the north of the state. The highest humidity is in the summer near the Great Lakes.

Required clothing

Warm winter clothes are needed in the coldest months. Light to mediumweights are advised for the summer. Rainwear may be useful.


Visa and passport information is updated regularly and is correct at the time of publishing. You should verify critical travel information independently with the relevant embassy before you travel.