January weather forecast
Sunnyvale, CA

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The perfect blue sky, trees, buildings, and cute water fountain all reflected in the calm pool of water with birds in Sunnyvale, California
The perfect blue sky, trees, buildings, and cute water fountain all reflected in the calm pool of water with birds in Sunnyvale, California

Weather in January

January in Sunnyvale, California, is characterized by a mild Winter with average high temperatures hovering around 58.3°F (14.6°C) and slightly cooler nights at around 44.6°F (7°C). The relative humidity measures at 72%, ensuring a bit of a nip in the air, particularly during early morning and nights. The month shows signs of precipitation, with rainfall noted on approximately six days of the month. With a healthy sunlight quota of approximately six hours a day, Sunnyvale enjoys a blend of winter and spring-like conditions in January. Despite being the coldest month of the year, January bears pleasant weather conditions conducive for various outdoor activities.

Temperature

January brings an average high-temperature of a still mild 58.3°F (14.6°C), showing a slight difference from December's 56.8°F (13.8°C). Sunnyvale records a mean low-temperature of 44.6°F (7°C) in January.

Humidity

The average relative humidity in January is 72%.

Rainfall

In January, in Sunnyvale, the rain falls for 6.3 days. Throughout January, 0.55" (14mm) of precipitation is accumulated. Throughout the year, in Sunnyvale, there are 50 rainfall days, and 3.9" (99mm) of precipitation is accumulated.

Daylight

The average length of the day in January in Sunnyvale is 9h and 56min.
On the first day of January in Sunnyvale, California, sunrise is at 7:22 am and sunset at 5:00 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 5:30 pm PST.

Sunshine

The average sunshine in January in Sunnyvale is 6.3h.

UV index

In January, the average daily maximum UV index in Sunnyvale is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for the ordinary person.
Note: In January, the UV index of 4 transforms into the following advice:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Opt for tightly woven and loose clothing to enhance protection from the Sun.
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Frequently asked questions

What is the usual temperature for Sunnyvale in January?

The high-temperature, in January, in Sunnyvale, is 58.3°F (14.6°C), while the low-temperature averages to 44.6°F (7°C).

What is the average humidity in January in Sunnyvale?

The average relative humidity in January in Sunnyvale is 72%.

How many days does it rain in January in Sunnyvale?

In January, in Sunnyvale, California, the rain falls for 6.3 days. Throughout January, 0.55" (14mm) of precipitation is accumulated.

How many hours of daylight does Sunnyvale have in January?

The average day length in January is 9h and 56min.

When is the sunrise / sunset in January in Sunnyvale?

In January, on the first day of the month, sunrise is at 7:22 am and sunset at 5:00 pm. On the last day of the month, in Sunnyvale, California, sunrise is at 7:12 am and sunset at 5:30 pm PST.

How long on average sun shines in January in Sunnyvale?

The average sunshine duration in January is 6.3h.

How high is the UV index in January in Sunnyvale?

In Sunnyvale, California, the average daily maximum UV index in January is 4. A UV Index reading of 3 to 5 represents a medium hazard to health from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in January
Sunnyvale, CA

Average temperature in January - Sunnyvale, CA
  • Average high temperature in January: 58.3°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 January: 44.6°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).

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Average pressure in January
Sunnyvale, CA

Average pressure in January - Sunnyvale, CA
  • Average pressure in January: 30.13"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).

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Average wind speed in January
Sunnyvale, CA

Average wind speed in January - Sunnyvale, CA
  • Average wind speed in January: 4.9mph

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).

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Average humidity in January
Sunnyvale, CA

Average humidity in January - Sunnyvale, CA
  • Average humidity in January: 72%

The month with the highest relative humidity is March (73%).
The months with the lowest relative humidity are September and October (63%).

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Average rainfall in January
Sunnyvale, CA

Average rainfall in January - Sunnyvale, CA
  • Average rainfall in January: 0.55"

The wettest months (with the highest rainfall) are February and March (0.75").
The driest month (with the least rainfall) is July (0").

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Average rainfall days in January
Sunnyvale, CA

Average rainfall days in January - Sunnyvale, CA
  • Average rainfall days in January: 6.3 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).

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Average daylight in January /
Average sunshine in January
Sunnyvale, CA

Average daylight in January / Average sunshine in January - Sunnyvale, CA
  • Average daylight in January: 9h and 5min

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 January: 6h and 2min

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).

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Average sunshine days in January
Sunnyvale, CA

Average sunshine days in January - Sunnyvale, CA
  • Average sunshine days in January: 23.8 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).

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Average UV index in January
Sunnyvale, CA

Average UV index in January - Sunnyvale, CA
  • Average UV index in January: 4

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).

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Average cloud cover in January
Sunnyvale, CA

Average cloud cover in January - Sunnyvale, CA
  • Average cloud cover in January: 30

The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 7).

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Average visibility in January
Sunnyvale, CA

Average visibility in January - Sunnyvale, CA
  • Average visibility in January: 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).

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Sunnyvale, California, USA

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