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
With average high temperatures of 57°F (13.9°C) and lows of 44.4°F (6.9°C), December is the coldest month.Humidity
In December, the average relative humidity in Cupertino is 71%.Rainfall
In Cupertino, California, during December, the rain falls for 8.2 days and regularly aggregates up to 0.87" (22mm) of precipitation. In Cupertino, California, during the entire year, the rain falls for 53.6 days and collects up to 5.39" (137mm) of precipitation.Daylight
December has the shortest days of the year, with an average of 9h and 36min of daylight.On the first day of the month, sunrise is at 7:04 am and sunset at 4:50 pm. On the last day of December, sunrise is at 7:22 am and sunset at 5:00 pm PST.
Sunshine
With an average of 5.9h of sunshine, December has the least sunshine of the year in Cupertino.UV index
January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for the average person.Note: The UV index of 3 during December translates into the following guidance:
Be vigilant - Preventing sunburn is recommended. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun.
Frequently asked questions
What time of the year is the coldest in Cupertino?
What is the usual temperature for Cupertino in December?
What is the average humidity in December in Cupertino?
How much does it rain in Cupertino in December?
What is the month with the shortest days in Cupertino?
How many hours of daylight does Cupertino have in December?
What time are sunrise and sunset in December in Cupertino?
What is the month with the least sunshine in Cupertino?
How long on average sun shines in December in Cupertino?
What are the months with the lowest UV index in Cupertino?
How high is the UV index in December in Cupertino?
Average temperature in December
Cupertino, CA
- Average high temperature in December: 57°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is December (57°F).
- Average low temperature in December: 44.4°F
The month with the highest average low temperature is August (56.1°F).
The coldest months (with the lowest average low temperature) are February and March (44.2°F).
Average pressure in December
Cupertino, CA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.92"Hg).
Average wind speed in December
Cupertino, CA
- Average wind speed in December: 5.3mph
The windiest month (with the highest average wind speed) is April (6.2mph).
The calmest month (with the lowest average wind speed) is September (4.6mph).
Average humidity in December
Cupertino, CA
- Average humidity in December: 71%
The month with the highest relative humidity is March (74%).
The months with the lowest relative humidity are July, September and October (64%).
Average rainfall in December
Cupertino, CA
- Average rainfall in December: 0.87"
The wettest month (with the highest rainfall) is February (1.02").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in December
Cupertino, CA
- Average rainfall days in December: 8.2 days
The month with the highest number of rainy days is March (9 days).
The month with the least rainy days is August (0.8 days).
Average daylight in December /
Average sunshine in December
Cupertino, CA
- Average daylight in December: 9h and 4min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in December: 5h and 5min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).
Average sunshine days in December
Cupertino, CA
- Average sunshine days in December: 21.5 days
The month with the most sunshine days is August (28.5 days).
The months with the least sunshine days are February and March (20.8 days).
Average UV index in December
Cupertino, CA
- Average UV index in December: 3
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in December
Cupertino, CA
- Average cloud cover in December: 33
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 7).
Average visibility in December
Cupertino, 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).
Cupertino, California, USA
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