September weather forecast
Mount Shasta, CA

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The Lake Siskiyou on the base of Mount Shasta in California, and a view of the planted forest, the far suspension bridge, and snowy mountain peak
The Lake Siskiyou on the base of Mount Shasta in California, and a view of the planted forest, the far suspension bridge, and snowy mountain peak

Weather in September

September, the first month of the autumn in Mount Shasta, is still a warm month, with an average temperature varying between 46.4°F (8°C) and 76.1°F (24.5°C).

Temperature

September heralds a minor drop in average high-temperature, sliding from August's warm 83.5°F (28.6°C) to a still moderately hot 76.1°F (24.5°C). Mount Shasta observes a noteworthy temperature drop from the daily highs during September nights, with a mean temperature of 46.4°F (8°C).

Humidity

In Mount Shasta, the average relative humidity in September is 50%.

Rainfall

In Mount Shasta, California, in September, during 4.1 rainfall days, 0.47" (12mm) of precipitation is typically accumulated. In Mount Shasta, California, during the entire year, the rain falls for 90.7 days and collects up to 26.38" (670mm) of precipitation.

Snowfall

Months with snowfall are January through May, September through December. September is the first month it typically snows in Mount Shasta, California. Throughout September, in the average 0.2 snowfall days, it receives 0.2" (5mm) of snow. In Mount Shasta, during the entire year, snow falls for 50.2 days and aggregates up to 81.42" (2068mm) of snow.

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, California, 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

The average sunshine in September in Mount Shasta is 11.1h.

UV index

In September, the average daily maximum UV index in Mount Shasta is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for average individuals.
Note: The maximum daily UV index of 4 in September converts into the following recommendations:
Guard yourself - An obligation to protect skin and eyes from harm exists. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Pay attention! The reflection of snow can enhance the Sun's UV radiation almost double.
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Frequently asked questions

What is the temperature in September in Mount Shasta?

During September, Mount Shasta experiences an average high-temperature of 76.1°F (24.5°C) and a low-temperature of 46.4°F (8°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), which combines air temperature and relative humidity, in August is estimated at 84.2°F (29°C).

What is the average humidity in September in Mount Shasta?

In September, the average relative humidity in Mount Shasta is 50%.

How much does it rain in Mount Shasta in September?

In Mount Shasta, California, in September, during 4.1 rainfall days, 0.47" (12mm) of precipitation is typically accumulated.

When does it start snowing in Mount Shasta?

September is the first month it typically snows in Mount Shasta, California. Throughout September, in the average 0.2 snowfall days, it receives 0.2" (5mm) of snow.

What is the average length of the day in September in Mount Shasta?

The average day length in September in Mount Shasta is 12h and 27min.

When is the sunrise / sunset in September in Mount Shasta?

In September, on the first day of the month, 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.

How many hours of sunshine does Mount Shasta have in September?

The average sunshine duration in September is 11.1h.

What is the UV index intensity in September in Mount Shasta?

In September, the average daily maximum UV index in Mount Shasta is 4. A UV Index reading of 3 to 5 represents a moderate health threat from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Mount Shasta, CA

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).

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Average pressure in September
Mount Shasta, CA

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).

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Average wind speed in September
Mount Shasta, CA

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).

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Average humidity in September
Mount Shasta, CA

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%).

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Average rainfall in September
Mount Shasta, CA

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").

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Average rainfall days in September
Mount Shasta, CA

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).

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Average snowfall in September
Mount Shasta, CA

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").

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Average snowfall days in September
Mount Shasta, CA

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).

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Average daylight in September /
Average sunshine in September
Mount Shasta, CA

Average daylight in September / Average sunshine in September - Mount Shasta, CA
  • Average daylight in September: 12h and 3min

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 1min

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).

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Average sunshine days in September
Mount Shasta, CA

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).

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Average UV index in September
Mount Shasta, CA

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).

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Average cloud cover in September
Mount Shasta, CA

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).

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Average visibility in September
Mount Shasta, CA

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).

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Mount Shasta, California, USA

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