Humidity Levels in Iowa During May

The average humidity in May is listed below for places in Iowa. 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 May
Daily Place Morning Afternoon
63 Des Moines 77 50
Dubuque 78 52
62 Sioux City 78 48
66 Waterloo 81 50

Highest and Lowest Humidity

Below are the averages during May for maximum and minimum humidity levels in Iowa. 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 May
High Time Place Low Time
77.1 6 am Des Moines 49.7 3 pm
78.0 6 am Dubuque 51.9 3 pm
78.3 6 am Sioux City 47.8 3 pm
81.0 6 am Waterloo 50.4 3 pm

World Data Center for Meteorology. Climate of the World.

Iowa Humidity
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