December weather forecast
Penryn, CA

Weather in December

December, the first month of the winter, in Penryn, is still a cool month, with average temperature ranging between min 39.2°F (4°C) and max 53.4°F (11.9°C).

Temperature

December is the coldest month, with an average high-temperature of 53.4°F (11.9°C) and an average low-temperature of 39.2°F (4°C).

Humidity

In Penryn, the average relative humidity in December is 68%.

Rainfall

In Penryn, in December, it is raining for 11.5 days, with typically 4.69" (119mm) of accumulated precipitation. Throughout the year, in Penryn, there are 84.8 rainfall days, and 28.86" (733mm) of precipitation is accumulated.

Snowfall

February, March and December are months with snowfall. December is the first month it typically snows in Penryn. Throughout December, in the average 0.3 snowfall days, it receives 0.63" (16mm) of snow. Throughout the year, in Penryn, there are 1.2 snowfall days, and 2.09" (53mm) of snow is accumulated.

Daylight

With an average of 9.5h of daylight, December has the shortest days of the year.

Sunshine

January and December, with an average of 5.8h of sunshine, are months with the least sunshine.

UV index

Months with the lowest UV index are January, February, November and December, with an average maximum UV index of 3. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to the Sun's UV rays for average individuals.
Note: In December, the average maximum UV index of 3 translate into the following recommendations:
Take precautions - Protection against the skin and eye damage is obliged. 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. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
[Resources]

FAQ

What is the coldest month in Penryn?

The coldest month in Penryn, California, is December, with an average high-temperature of 53.4°F (11.9°C) and an average low-temperature of 39.2°F (4°C).

What is the average humidity in December in Penryn?

In Penryn, California, the average relative humidity in December is 68%.

How much does it rain in Penryn in December?

In Penryn, California, during December, the rain falls for 11.5 days and regularly aggregates up to 4.69" (119mm) of precipitation.

When does it start snowing in Penryn?

December is the first month it typically snows in Penryn, California. Throughout December, in the average 0.3 snowfall days, it receives 0.63" (16mm) of snow.

What is the month with the shortest days in Penryn?

December has the shortest days of the year in Penryn, California, with an average of 9.5h of daylight.

How many hours of daylight does Penryn have in December?

The average length of the day in December in Penryn, California, is 9.5h.

What is the month with the least sunshine in Penryn?

January and December, with an average of 5.8h of sunshine, are months with the least sunshine.

How many hours of sunshine does Penryn have in December?

The average sunshine in December in Penryn is 5.8h.

When is the lowest UV index in Penryn?

January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index in Penryn, California.

What is the UV index reading in December in Penryn?

In Penryn, the average daily maximum UV index in December is 3. A UV Index estimate of 3 to 5 represents a medium health risk from the exposure to the Sun's UV radiation.

Average temperature in December
Penryn, CA

Average temperature in December - Penryn, CA
  • Average high temperature in December: 53.4°F

The warmest month (with the highest average high temperature) is July (91.9°F).
The month with the lowest average high temperature is December (53.4°F).

  • Average low temperature in December: 39.2°F

The month with the highest average low temperature is July (60.6°F).
The coldest month (with the lowest average low temperature) is December (39.2°F).

[Resources]

Average pressure in December
Penryn, CA

Average pressure in December - Penryn, 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 (29.9").

[Resources]

Average wind speed in December
Penryn, CA

Average wind speed in December - Penryn, CA
  • Average wind speed in December: 4.9mph

The windiest months (with the highest average wind speed) are February and March (5.7mph).
The calmest month (with the lowest average wind speed) is August (4.3mph).

[Resources]

Average humidity in December
Penryn, CA

Average humidity in December - Penryn, CA
  • Average humidity in December: 68%

The month with the highest relative humidity is March (75%).
The month with the lowest relative humidity is July (38%).

[Resources]

Average rainfall in December
Penryn, CA

Average rainfall in December - Penryn, CA
  • Average rainfall in December: 4.69"

The wettest month (with the highest rainfall) is March (5.63").
The driest months (with the least rainfall) are July and August (0.04").

[Resources]

Average rainfall days in December
Penryn, CA

Average rainfall days in December - Penryn, CA
  • Average rainfall days in December: 11.5 days

The month with the highest number of rainy days is March (15.4 days).
The month with the least rainy days is July (1 days).

[Resources]

Average snowfall in December
Penryn, CA

Average snowfall in December - Penryn, CA
  • Average snowfall in December: 0.63"

The month with the highest snowfall is February (1.18").
Months with the least snowfall are January, April, May, June, July, August, September, October and November (0").

[Resources]

Average snowfall days in December
Penryn, CA

Average snowfall days in December - Penryn, CA
  • Average snowfall days in December: 0.3 days

The month with the highest number of snowfall days is February (0.6 days).
Months with the least snowfall days are January, April, May, June, July, August, September, October and November (0 days).

[Resources]

Average daylight in December /
Average sunshine in December
Penryn, CA

Average daylight in December / Average sunshine in December - Penryn, CA
  • Average daylight in December: 9.5h

The month with the longest days is June (Average daylight: 14.9h).
The month with the shortest days is December (Average daylight: 9.5h).

  • Average sunshine in December: 5.8h

The month with the most sunshine is July (Average sunshine: 12.1h).
Months with the least sunshine are January and December (Average sunshine: 5.8).

[Resources]

Average sunshine days in December
Penryn, CA

Average sunshine days in December - Penryn, CA
  • Average sunshine days in December: 18.7 days

The month with the most sunshine days is July (29.6 days).
The month with the least sunshine days is March (14.6 days).

[Resources]

Average UV index in December
Penryn, CA

Average UV index in December - Penryn, CA
  • Average UV index in December: 3

Months with the highest UV index are June and July (UV index 7).
Months with the lowest UV index are January, February, November and December (UV index 3).

[Resources]

Average cloud cover in December
Penryn, CA

Average cloud cover in December - Penryn, CA
  • Average cloud cover in December: 34

The month with the most cloud cover is March (Cloud cover 41).
The month with the least cloud cover is July (Cloud cover 4).

[Resources]

Average visibility in December
Penryn, CA

Average visibility in December - Penryn, 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).

[Resources]

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location
* you will be automatically redirected to the weather forecast for your location