Humidity Levels in Illinois During August

The average humidity in August 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 relative humidity (%) in August
Daily Place Morning Afternoon
71 Chicago 85 55
73 Moline 89 55
74 Peoria 89 56
74 Rockford 90 55
74 Springfield 89 57

Highest and Lowest Humidity

Below are the averages during August for maximum and minimum humidity levels in Illinois. The hours when this month's highest and lowest humidity readings usually occur are given in local standard time.

Daily high and low relative humidity (%) averages in August
High Time Place Low Time
84.9 6 am Chicago 54.8 3 pm
88.9 6 am Moline 54.8 3 pm
88.6 6 am Peoria 56.1 3 pm
90.2 6 am Rockford 55.2 3 pm
88.9 6 am Springfield 56.5 3 pm

World Data Center for Meteorology. Climate of the World.

Illinois Humidity
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