Humidity Levels in California During September

The average humidity in September is listed below for places in California. 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
Southern California
44 Bakersfield 57 29
69 Long Beach 80 54
74 Los Angeles 80 67
73 San Diego 77 65
74 Santa Barbara 83 64
81 Santa Maria 88 62
Northern California
50 Fresno 69 28
57 Sacramento 76 31
72 San Francisco 82 58
52 Stockton 70 30

Highest and Lowest Humidity

Below are the averages during September for maximum and minimum humidity levels in California. 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
Southern California
58.0 4 am Bakersfield 28.7 4 pm
82.1 4 am Long Beach 51.8 1 pm
82.7 4 am Los Angeles 61.8 1 pm
79.9 4 am San Diego 62.3 1 pm
82.9 4 am Santa Barbara 60.7 1 pm
93.0 1 am Santa Maria 55.9 1 pm
Northern California
71.7 4 am Fresno 28.0 4 pm
77.2 4 am Sacramento 31.3 4 pm
83.3 4 am San Francisco 53.3 1 pm
70.3 7 am Stockton 30.3 4 pm
Reference

World Data Center for Meteorology. Climate of the World.

California Humidity
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