December weather forecast and climate
Mammoth Lakes, CA

Perfect water reflections of trees, rocks, and distant mountains in the clear water of Mammoth Lakes, California
Perfect water reflections of trees, rocks, and distant mountains in the clear water of Mammoth Lakes, California

Weather in December

December, the first month of the winter, in Mammoth Lakes, is still a cold month, with average temperature varying between 34.2°F (1.2°C) and 15.4°F (-9.2°C).

Temperature

In Mammoth Lakes, the average high-temperature decreases, from a chilly 44.4°F (6.9°C) in November, to a wintry 34.2°F (1.2°C). The average low-temperature, in Mammoth Lakes, California, is 15.4°F (-9.2°C).

Humidity

In December, the average relative humidity is 71%.

Rainfall

In December, the rain falls for 4.8 days. Throughout December, 0.63" (16mm) of precipitation is accumulated. Throughout the year, in Mammoth Lakes, there are 47.7 rainfall days, and 4.92" (125mm) of precipitation is accumulated.

Snowfall

Months with snowfall in Mammoth Lakes are January through June, September through December. In December, in Mammoth Lakes, it is snowing for 9.5 days. Throughout December, 4.92" (125mm) of snow is accumulated. In Mammoth Lakes, during the entire year, snow falls for 60.8 days, and aggregates up to 28.58" (726mm) of snow.

Daylight

December has the shortest days of the year in Mammoth Lakes, with an average of 9.6h of daylight.

Sunshine

In Mammoth Lakes, the average sunshine in December is 6.4h.

UV index

Months with the lowest UV index in Mammoth Lakes are January through April, October through December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a low health risk from the exposure to the Sun's UV rays for ordinary individuals.
Note: In December, the average maximum UV index of 2 translate into the following recommendations:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.
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FAQ

What is the temperature in December in Mammoth Lakes?

In Mammoth Lakes, California, in December, the average high-temperature is 34.2°F (1.2°C), and the average low-temperature is 15.4°F (-9.2°C).

What is the average humidity in December in Mammoth Lakes?

In Mammoth Lakes, the average relative humidity in December is 71%.

How much does it rain in Mammoth Lakes in December?

In December, in Mammoth Lakes, the rain falls for 4.8 days. Throughout December, 0.63" (16mm) of precipitation is accumulated.

How many days does it snow in December in Mammoth Lakes?

In Mammoth Lakes, California, in December, snow falls for 9.5 days, with typically accumulated 4.92" (125mm) of snow.

What is the month with the shortest days in Mammoth Lakes?

December has the shortest days of the year, with an average of 9.6h of daylight.

How many hours of daylight does Mammoth Lakes have in December?

In Mammoth Lakes, the average length of the day in December is 9.6h.

How many hours of sunshine does Mammoth Lakes have in December?

In December, the average sunshine in Mammoth Lakes is 6.4h.

What are the months with the lowest UV index in Mammoth Lakes?

Months with the lowest UV index in Mammoth Lakes, California, are January through April, October through December, with an average maximum UV index of 2.

What is the UV index reading in December in Mammoth Lakes?

In December, the average daily maximum UV index in Mammoth Lakes, California, is 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to the UV radiation.

Average temperature in December
Mammoth Lakes, CA

Average temperature in December - Mammoth Lakes, CA
  • Average high temperature in December: 34.2°F

The warmest month (with the highest average high temperature) is July (73.4°F).
The month with the lowest average high temperature is February (34°F).

  • Average low temperature in December: 15.4°F

The month with the highest average low temperature is July (48.2°F).
The coldest month (with the lowest average low temperature) is February (14.9°F).

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Average pressure in December
Mammoth Lakes, CA

Average pressure in December - Mammoth Lakes, CA
  • Average pressure in December: 30.13"

The month with the highest atmospheric pressure is January (30.16").
The month with the lowest atmospheric pressure is June (29.89").

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Average wind speed in December
Mammoth Lakes, CA

Average wind speed in December - Mammoth Lakes, CA
  • Average wind speed in December: 6.1mph

The windiest month (with the highest average wind speed) is March (6.9mph).
The calmest months (with the lowest average wind speed) are July and August (4.9mph).

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Average humidity in December
Mammoth Lakes, CA

Average humidity in December - Mammoth Lakes, CA
  • Average humidity in December: 71%

The month with the highest relative humidity is February (76%).
The month with the lowest relative humidity is August (34%).

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Average rainfall in December
Mammoth Lakes, CA

Average rainfall in December - Mammoth Lakes, CA
  • Average rainfall in December: 0.63"

The wettest month (with the highest rainfall) is February (0.94").
The driest months (with the least rainfall) are August and October (0.08").

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Average rainfall days in December
Mammoth Lakes, CA

Average rainfall days in December - Mammoth Lakes, CA
  • Average rainfall days in December: 4.8 days

The month with the highest number of rainy days is April (6.3 days).
The month with the least rainy days is August (1.8 days).

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Average snowfall in December
Mammoth Lakes, CA

Average snowfall in December - Mammoth Lakes, CA
  • Average snowfall in December: 4.92"

The month with the highest snowfall is February (5.67").
Months with the least snowfall are July and August (0").

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Average snowfall days in December
Mammoth Lakes, CA

Average snowfall days in December - Mammoth Lakes, CA
  • Average snowfall days in December: 9.5 days

The month with the highest number of snowfall days is March (11.3 days).
Months with the least snowfall days are July and August (0 days).

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Average daylight in December /
Average sunshine in December
Mammoth Lakes, CA

Average daylight in December / Average sunshine in December - Mammoth Lakes, CA
  • Average daylight in December: 9.6h

The month with the longest days is June (Average daylight: 14.7h).
The month with the shortest days is December (Average daylight: 9.6h).

  • Average sunshine in December: 6.4h

Months with the most sunshine are July and August (Average sunshine: 12h).
The month with the least sunshine is January (Average sunshine: 6.3h).

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Average sunshine days in December
Mammoth Lakes, CA

Average sunshine days in December - Mammoth Lakes, CA
  • Average sunshine days in December: 21.3 days

The month with the most sunshine days is October (27.3 days).
The month with the least sunshine days is March (18.2 days).

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Average UV index in December
Mammoth Lakes, CA

Average UV index in December - Mammoth Lakes, CA
  • Average UV index in December: 2

Months with the highest UV index are June and July (UV index 5).
Months with the lowest UV index are January, February, March, April, October, November and December (UV index 2).

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Average cloud cover in December
Mammoth Lakes, CA

Average cloud cover in December - Mammoth Lakes, CA
  • Average cloud cover in December: 29

The month with the most cloud cover is March (Cloud cover 30).
The month with the least cloud cover is August (Cloud cover 7).

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Average visibility in December
Mammoth Lakes, CA

Average visibility in December - Mammoth Lakes, CA
  • Average visibility in December: 6mi

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

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