Humidity Levels in Oregon During September

The average humidity in September is listed below for places in Oregon. 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 7 am and Afternoon measures are for 4 pm local standard time.

Average relative humidity (%) in September
Daily Place Morning Afternoon
81 Astoria 90 69
70 Eugene 89 45
57 Medford 79 30
47 Pendleton 61 32
69 Portland 86 48
69 Salem 86 45

Highest and Lowest Humidity

Below are the averages during September for maximum and minimum humidity levels in Oregon. 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 September
High Time Place Low Time
90.0 4 am Astoria 67.8 1 pm
89.1 7 am Eugene 44.5 4 pm
79.0 4 am Medford 30.3 4 pm
61.0 4 am Pendleton 31.7 4 pm
85.9 7 am Portland 47.9 4 pm
87.3 4 am Salem 45.3 4 pm

World Data Center for Meteorology. Climate of the World.

Oregon Humidity
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