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
Sunnyvale's coldest month, December, generally records average temperatures ranging from a high of 56.8°F (13.8°C) to a low of 44.2°F (6.8°C).Humidity
The average relative humidity in December in Sunnyvale is 71%.Rainfall
In Sunnyvale, during December, the rain falls for 7.5 days and regularly aggregates up to 0.71" (18mm) of precipitation. In Sunnyvale, during the entire year, the rain falls for 50 days and collects up to 3.9" (99mm) of precipitation.Daylight
With an average of 9h and 36min of daylight, December has the shortest days of the year.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
The month with the least sunshine in Sunnyvale is December, with an average of 5.9h of sunshine.UV index
The months with the lowest UV index in Sunnyvale are February, November and December, with an average maximum UV index of 3. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: The maximum daily UV index of 3 during December translates into the following directions:
Exercise prevention - Protecting skin and eyes from harm is required. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat.
Frequently asked questions
What are the coldest months in Sunnyvale?
What is the usual temperature for Sunnyvale in December?
What is the average humidity in December in Sunnyvale?
How many days does it rain in December in Sunnyvale?
What is the month with the shortest days in Sunnyvale?
What is the average length of the day in December in Sunnyvale?
When are sunrise and sunset in December in Sunnyvale?
What is the month with the least sunshine in Sunnyvale?
How many hours of sunshine does Sunnyvale have in December?
When is the lowest UV index in Sunnyvale?
How high is the UV index in December in Sunnyvale?
Average temperature in December
Sunnyvale, CA
- Average high temperature in December: 56.8°F
The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is December (56.8°F).
- Average low temperature in December: 44.2°F
The month with the highest average low temperature is August (56.8°F).
The coldest months (with the lowest average low temperature) are February and December (44.2°F).
Average pressure in December
Sunnyvale, CA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June and September (29.92"Hg).
Average wind speed in December
Sunnyvale, 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
Sunnyvale, CA
- Average humidity in December: 71%
The month with the highest relative humidity is March (73%).
The months with the lowest relative humidity are September and October (63%).
Average rainfall in December
Sunnyvale, CA
- Average rainfall in December: 0.71"
The wettest months (with the highest rainfall) are February and March (0.75").
The driest month (with the least rainfall) is July (0").
Average rainfall days in December
Sunnyvale, CA
- Average rainfall days in December: 7.5 days
The month with the highest number of rainy days is March (9.6 days).
The month with the least rainy days is August (0.4 days).
Average daylight in December /
Average sunshine in December
Sunnyvale, 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 month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).
Average sunshine days in December
Sunnyvale, CA
- Average sunshine days in December: 22.4 days
The month with the most sunshine days is August (30.1 days).
The month with the least sunshine days is March (19.9 days).
Average UV index in December
Sunnyvale, 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 February, November and December (UV index 3).
Average cloud cover in December
Sunnyvale, 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
Sunnyvale, 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).
Sunnyvale, California, USA
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