Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
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.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the coldest months?
What is the usual temperature for Princeton in December?
What is the average humidity in December?
What is the rainiest month?
How much does it rain in December?
What is the month with the shortest days?
What is the average length of the day in December?
When is the sunrise / sunset in December?
What is the month with the least sunshine?
How long on average sun shines in December?
What are the months with the lowest UV index?
What is the UV index reading in December in Princeton?
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 2min
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 5min
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).
Princeton, California, USA
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