December weather forecastPrinceton, CA

December

Weather in December

December, the first month of the winter in Princeton, is also a fresh month, with temperature in the range of an average low of 42.1°F (5.6°C) and an average high of 54.5°F (12.5°C).

Temperature

December tends to be the coldest month, with temperatures averaging a daily high of 54.5°F (12.5°C) and a low of 42.1°F (5.6°C).

Humidity

In December, the average relative humidity in Princeton is 67%.

Rainfall

The months with the most rainfall are February and December, with an average 1.3" (33mm) of precipitation.

Daylight

The month with the shortest days is December, with an average of 9h and 24min of daylight.
On the first day of December, sunrise is at 7:09 am and sunset at 4:45 pm. On the last day of the month, sunrise is at 7:27 am and sunset at 4:54 pm PST.

Sunshine

December has the least sunshine of the year, with an average of 5.8h of sunshine.

UV index

The months with the lowest UV index are February, November and December, with an average maximum UV index of 3. A UV Index of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: A daily high UV index of 3 in December leads to these guidelines:
Adopt protective measures - Suggestions to resist sunburn are offered. When the Sun is at its strongest around midday, find shade and limit exposure. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense.
Updated: Aug 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Princeton experiences its lowest temperatures in December, with an average peak of 54.5°F (12.5°C) and a low of 42.1°F (5.6°C).

The high-temperature during December is 54.5°F (12.5°C) and the low-temperature is 42.1°F (5.6°C). In June, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which represents the influence of relative humidity on air temperature, is calculated to be 93.2°F (34°C).

The average relative humidity in December is 67%.

The wettest months are February and December, with an average 1.3" (33mm) of rainfall.

In Princeton, in December, during 7.6 rainfall days, 1.3" (33mm) of precipitation is typically accumulated.

With an average of 9h and 24min of daylight, December has the shortest days of the year.

The average day length in December is 9h and 27min.

On the first day of December, sunrise is at 7:09 am and sunset at 4:45 pm. On the last day of the month, sunrise is at 7:27 am and sunset at 4:54 pm PST.

The month with the least sunshine is December, with an average of 5.8h of sunshine.

In December, the average sunshine duration is 5.8h.

The months with the lowest UV index are February, November and December, with an average maximum UV index of 3.

The average daily maximum UV index in December is 3. A UV Index value of 3 to 5 symbolizes a medium health risk from unprotected exposure to UV radiation.
Average high temperature
Average low temperature
Average pressure
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Princeton, CA

  • Average high temperature in December: 54.5°F

The warmest month (with the highest average high temperature) is July (98.8°F).
The month with the lowest average high temperature is December (54.5°F).

  • Average low temperature in December: 42.1°F

The month with the highest average low temperature is July (61.5°F).
The coldest month (with the lowest average low temperature) is December (42.1°F).

Average pressure in December
Princeton, CA

  • Average pressure in December: 30.12"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in December
Princeton, CA

  • Average wind speed in December: 5.9mph

The windiest month (with the highest average wind speed) is March (6.6mph).
The calmest month (with the lowest average wind speed) is August (5mph).

Average humidity in December
Princeton, CA

  • Average humidity in December: 67%

The month with the highest relative humidity is March (71%).
The month with the lowest relative humidity is September (36%).

Average rainfall in December
Princeton, CA

  • Average rainfall in December: 1.3"

The wettest months (with the highest rainfall) are February and December (1.3").
The driest months (with the least rainfall) are July and August (0.04").

Average rainfall days in December
Princeton, CA

  • Average rainfall days in December: 7.6 days

The month with the highest number of rainy days is March (10.4 days).
The month with the least rainy days is July (1 days).

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

  • Average daylight in December: 9h and 24min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).

  • Average sunshine in December: 5h and 48min

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 48min).

Average sunshine days in December
Princeton, CA

  • Average sunshine days in December: 22.5 days

The month with the most sunshine days is July (29.8 days).
The month with the least sunshine days is March (19.7 days).

Average UV index in December
Princeton, CA

  • Average UV index in December: 3

The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are February, November and December (UV index 3).

Average cloud cover in December
Princeton, CA

  • Average cloud cover in December: 36

The months with the most cloud cover are March and December (Cloud cover 36).
The month with the least cloud cover is July (Cloud cover 4).

Average visibility in December
Princeton, CA

  • Average visibility in December: 6mi

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