Annual Average Humidity in Illinois

The average humidity year round is listed below for places in Illinois. The tables give daily averages along with highest and lowest relative humidity levels.

Relative humidity measures the actual amount of moisture in the air as a percentage of the maximum amount of moisture the air can hold.

All the numbers here are averages for the years 1961 to 1990.

Average Humidity

In this table, the Daily number is the average of humidity readings taken every three hours throughout the day. Morning percentages are for 6 am and Afternoon measures are for 3 pm local standard time.

Average yearly relative humidity (%)
Daily Place Morning Afternoon
70 Chicago 80 57
69 Moline 80 56
72 Peoria 83 58
72 Rockford 83 57
71 Springfield 83 57

Highest and Lowest Humidity

Below are averages over the year for maximum and minimum humidity levels in Illinois. The hours when the highest and lowest humidity readings usually occur are given in local standard time.

Annual averages for daily high and low relative humidity (%)
High Time Place Low Time
79.8 6 am Chicago 57.3 3 pm
80.3 6 am Moline 55.6 3 pm
82.7 6 am Peoria 57.8 3 pm
83.2 6 am Rockford 57.4 3 pm
82.6 6 am Springfield 57.3 3 pm

World Data Center for Meteorology. Climate of the World.

Illinois Humidity
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