Temperatures in December
It's cool to moderate in December in Sunnyvale with an average temperature of 16°C. Temperatures this month range from a low of 14°C to a high of 17°C. At night, you can expect temperatures between 6°C and 9°C.
Max and Min Temperatures per Day
This chart shows the daily maximum and minimum temperatures in degrees Celsius for Sunnyvale in December. The red line indicates the max temperatures, and the blue line shows the minimums.
Start of December
The month of December starts in Sunnyvale with cool temperatures, averaging around 17°C during the day and nights close to 8°C. A few showers might pop up in the first days of the month, but the weather remains mostly sunny and dry.
Mid-December
By mid-December, the average daytime temperature drops to around 16°C, with nights close to 8°C. There might be a few showers during this period, but plenty of dry days with sunshine too.
End of December
By the end of December, the average daytime temperature in Sunnyvale will be around 15°C, with nights close to 7°C. A shower might show up, but overall the weather will be dry and sunny.
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Precipitation in December
In December, there is an average of 94 mm of precipitation, spread over 8 days. The wind speed is around 3 Bft, mostly coming from the West.
The average precipitation chance is 26% per day this month. Though it seems pretty low, the weather’s variable. Some days have higher and others lower precipitation chances, which lowers the average.
Precipitation Chance
This chart shows the daily precipitation chance (in percentages) in December for Sunnyvale. 0% means it never rained on that day in the past 10 years, and 100% means it rained every day. All values in between represent the average chance of precipitation on that day.
Sunnyvale in December |
London | ||
|---|---|---|---|
 Average Temperature |
16°C | 9°C | |
 High Temp |
17°C | 11°C | |
| Low Temp |
14°C | 8°C | |
 Total Precipitation |
94 mm | 67 mm | |
| Rainy Days |
8 days | 10 days | |
November
UV index
The UV index is a maximum of 3 this month. That's a moderate value on the intensity scale of 1 to 11. Unprotected skin can burn in about 30 minutes.
Is December a good time to visit Sunnyvale?
Looking for sun and warm weather? Then December isn’t the best time to be in Sunnyvale. The temperature is too low this month for a warm stay.
Temperature records for Sunnyvale in December
With 23°C, Sunnyvale hit the highest temperature in the last 10 years in December 2020. The lowest daytime temperature in this month was 8°C in 2015. The extreme night temperatures ranged from a low of -1°C to a high of 16°C.
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Daily Temperature in December in Sunnyvale
This chart shows the average daily temperatures, both day and night, for each day in December in Sunnyvale, measured in degrees Celsius. The red line represents the maximum temperatures, while the blue line shows the minimums. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, gives an overview of the average daily temperatures during this month.
Daily Precipitation in December in Sunnyvale
The chart below shows the average daily precipitation in December for Sunnyvale, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are shown at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that rain is more likely. But it’s still an average, so each day can be different. Based on historical weather data for December, you can expect around 8 days of rain in Sunnyvale.
Daily UV Index in December in Sunnyvale
This chart shows the average daily UV index in December in Sunnyvale, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Temperature in December in Sunnyvale Over the Years
This chart shows the average temperature in December in Sunnyvale, measured in degrees Celsius, over the past years.
Total Precipitation in December in Sunnyvale Over the Years
This chart shows the average precipitation in December in Sunnyvale, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail.
Daily climate in December for Sunnyvale
Click on a specific day in December for detailed info on the typical weather on that day in Sunnyvale. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in December in Sunnyvale
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Average Weather in Sunnyvale by Month
Click on a month below to see detailed weather info for Sunnyvale. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
Or check out the climate of Sunnyvale for all months at once
