September weather forecastMount Shasta, CA

September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Mount Shasta, California, with temperature in the range of an average high of 76.1°F (24.5°C) and an average low of 46.4°F (8°C).Temperature
In September, the average high-temperature marginally drops from a warm 83.5°F (28.6°C) in August to a still moderately hot 76.1°F (24.5°C). Mount Shasta registers a significant drop in temperature in September, with average nighttime lows of 46.4°F (8°C).Humidity
In September, the average relative humidity is 50%.Rainfall
In Mount Shasta, in September, during 4.1 rainfall days, 0.47" (12mm) of precipitation is typically accumulated. Throughout the year, there are 90.7 rainfall days, and 26.38" (670mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.2" (5mm) of snow. Throughout the year, there are 50.2 snowfall days, and 81.42" (2068mm) of snow is accumulated.Daylight
In September, the average length of the day in Mount Shasta is 12h and 27min.On the first day of September in Mount Shasta, sunrise is at 6:36 am and sunset at 7:41 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 6:52 pm PDT.
Sunshine
In September, the average sunshine is 11.1h.UV index
In Mount Shasta, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: The maximum UV index of 4 during September leads to these instructions:
Take precautions - Protection against sun damage is advised. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear. Be prepared! The intensity of the Sun's UV radiation can be amplified nearly double due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mount Shasta, CA
- Average high temperature in September: 76.1°F
The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is December (40.8°F).
- Average low temperature in September: 46.4°F
The month with the highest average low temperature is July (52.2°F).
The coldest month (with the lowest average low temperature) is December (27.1°F).
Average pressure in September
Mount Shasta, CA
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The months with the lowest atmospheric pressure are June and August (29.94"Hg).
Average wind speed in September
Mount Shasta, CA
- Average wind speed in September: 4.5mph
The windiest month (with the highest average wind speed) is March (5.8mph).
The calmest month (with the lowest average wind speed) is August (3.9mph).
Average humidity in September
Mount Shasta, CA
- Average humidity in September: 50%
The month with the highest relative humidity is March (81%).
The month with the lowest relative humidity is August (45%).
Average rainfall in September
Mount Shasta, CA
- Average rainfall in September: 0.47"
The wettest month (with the highest rainfall) is March (4.69").
The driest month (with the least rainfall) is July (0.16").
Average rainfall days in September
Mount Shasta, CA
- Average rainfall days in September: 4.1 days
The month with the highest number of rainy days is March (12.3 days).
The month with the least rainy days is August (2.3 days).
Average snowfall in September
Mount Shasta, CA
- Average snowfall in September: 0.2"
The month with the highest snowfall is January (19.21").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Mount Shasta, CA
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is December (10.9 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Mount Shasta, CA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 11h and 6min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 24min).
Average sunshine days in September
Mount Shasta, CA
- Average sunshine days in September: 24 days
The months with the most sunshine days are July and August (25.7 days).
The month with the least sunshine days is March (12.3 days).
Average UV index in September
Mount Shasta, CA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Mount Shasta, CA
- Average cloud cover in September: 12
The month with the most cloud cover is March (Cloud cover 45).
The month with the least cloud cover is August (Cloud cover 6).
Average visibility in September
Mount Shasta, CA
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February, March and December (5mi).





