Sunnyvale Weather in December

With daytime temperatures of 15°C (59°F) and nighttime lows of 5°C (41°F), December in Sunnyvale brings moderate temperatures during the day. It is also the wettest month of the year, so pack an umbrella.

Rainfall in Sunnyvale in December

Prepare for the wettest month with an umbrella to protect yourself from frequent rain. Typically, you can expect about 11 days of rain this month, with 70 mm (2.8 in) on average. Rain this month is fairly typical, a standard mix of wet and dry days with no particularly heavy or persistent showers.

Temperature in Sunnyvale in December

December in Sunnyvale brings moderate temperatures, with highs of 15°C (59°F) and nights around 5°C (41°F). The month of December belongs to the winter season. A light jacket or extra layer can be useful, especially outside the warmest hours of the day. With overnight lows of 5°C (41°F), nights are cold. The cold air does make for deep, comfortable sleep if you have enough blankets. During this period, the city experiences its coolest temperatures annually.

Sunshine in Sunnyvale in December

The city usually sees around 160 hours of sunlight, indicating a moderately sunny period.

If you're looking for dry conditions and comfortable temperatures, December may not be the ideal month to visit Sunnyvale. Our weather planner can help you explore destinations with more pleasant weather conditions.

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Check the conditions for any month of the year.

• January
• February
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• May
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• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Sunnyvale's climate page.

Sunnyvale Temperature in December

Min Temperature 5°C (41°F)  

Max Temperature 15°C (59°F)  

Chance of Rain 36%  

Precipitation 70 mm (2.8 in)  

Rainy days 11 days  

Humidity 78% *  

Sunshine 160 hours *  

Percentage Sunshine 54% *  

* Data from: San Francisco, the United States of America (41 KM, 25 Miles).

What to Wear in Sunnyvale in December

The weather can swing between comfortable and chilly in December, so flexibility is key. Pack a variety of tops, at least one warm layer, and both shorts and long pants. This gives you options no matter what the day brings. Wet weather is likely, so pack waterproof gear for multiple rainy days. Bring sunglasses since you'll have some sunny periods throughout the month

What To Do in Sunnyvale in December

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

5/10

Cycling

6/10

Walking

6/10

Camping

4/10

Outdoor sports

9/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Sunnyvale's climate page.

More climate data for Sunnyvale

Temperature Rainfall Sunshine Humidity

See the full Sunnyvale climate overview or explore weather in the United States of America.