January weather forecast and climate
Vallejo, CA

A colorful orange sunset skyline seen over the Napa River and Bridge in Vallejo, California
A colorful orange sunset skyline seen over the Napa River and Bridge in Vallejo, California

Weather in January

January, the same as December, in Vallejo, California, is another mild winter month, with average temperature varying between 43°F (6.1°C) and 56.5°F (13.6°C).

Temperature

In Vallejo, the average high-temperature is relatively the same as in December - a still moderate 56.5°F (13.6°C). The average low-temperature, in Vallejo, is 43°F (6.1°C).

Humidity

In January, the average relative humidity in Vallejo is 73%.

Rainfall

In January, the rain falls for 7.7 days. Throughout January, 0.83" (21mm) of precipitation is accumulated. In Vallejo, during the entire year, the rain falls for 56.9 days and collects up to 4.88" (124mm) of precipitation.

Daylight

In January, the average length of the day is 9.9h.

Sunshine

The average sunshine in Vallejo is 5.9h.

UV index

Months with the lowest UV index in Vallejo are January, February, November and December, with an average maximum UV index of 3. A UV Index value of 3 to 5 symbolizes a medium vulnerability from the exposure to the Sun's UV radiation for the ordinary person.
Note: The daily maximum UV index of 3 interpret into the following advice:
Take precautions - Protection against sunburn is recommended. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
[Resources]

FAQ

What is the temperature in January in Vallejo?

In Vallejo, in January, the average high-temperature is 56.5°F (13.6°C), and the average low-temperature is 43°F (6.1°C).

What is the average humidity in January in Vallejo?

In January, the average relative humidity is 73%.

How many days does it rain in January in Vallejo?

In Vallejo, in January, during 7.7 rainfall days, 0.83" (21mm) of precipitation is typically accumulated.

What is the average length of the day in January in Vallejo?

The average length of the day in January in Vallejo is 9.9h.

How many hours of sunshine does Vallejo have in January?

In January, the average sunshine in Vallejo, California, is 5.9h.

What is the month with the lowest UV index in Vallejo?

Months with the lowest UV index are January, February, November and December, with an average maximum UV index of 3.

What is the UV index intensity in January in Vallejo?

In January, the average daily maximum UV index is 3. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from unprotected exposure to the UV radiation.

Average temperature in January
Vallejo, CA

Average temperature in January - Vallejo, CA
  • Average high temperature in January: 56.5°F

The warmest months (with the highest average high temperature) are July and September (80.1°F).
The month with the lowest average high temperature is December (55.4°F).

  • Average low temperature in January: 43°F

The month with the highest average low temperature is August (56.5°F).
The coldest month (with the lowest average low temperature) is January (43°F).

[Resources]

Average pressure in January
Vallejo, CA

Average pressure in January - Vallejo, CA
  • Average pressure in January: 30.14"

The month with the highest atmospheric pressure is January (30.14").
The month with the lowest atmospheric pressure is June (29.91").

[Resources]

Average wind speed in January
Vallejo, CA

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

The windiest month (with the highest average wind speed) is May (7.1mph).
The calmest month (with the lowest average wind speed) is November (4.6mph).

[Resources]

Average humidity in January
Vallejo, CA

Average humidity in January - Vallejo, CA
  • Average humidity in January: 73%

The month with the highest relative humidity is March (75%).
Months with the lowest relative humidity are September and October (60%).

[Resources]

Average rainfall in January
Vallejo, CA

Average rainfall in January - Vallejo, CA
  • Average rainfall in January: 0.83"

The wettest month (with the highest rainfall) is February (1.14").
The driest months (with the least rainfall) are July and August (0.04").

[Resources]

Average rainfall days in January
Vallejo, CA

Average rainfall days in January - Vallejo, CA
  • Average rainfall days in January: 7.7 days

The month with the highest number of rainy days is March (10.2 days).
The month with the least rainy days is August (0.9 days).

[Resources]

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

Average daylight in January / Average sunshine in January - Vallejo, CA
  • Average daylight in January: 9.9h

The month with the longest days is June (Average daylight: 14.8h).
The month with the shortest days is December (Average daylight: 9.6h).

  • Average sunshine in January: 5.9h

The month with the most sunshine is July (Average sunshine: 12h).
The month with the least sunshine is December (Average sunshine: 5.7h).

[Resources]

Average sunshine days in January
Vallejo, CA

Average sunshine days in January - Vallejo, CA
  • Average sunshine days in January: 21.8 days

The month with the most sunshine days is July (27.2 days).
The month with the least sunshine days is March (18.8 days).

[Resources]

Average UV index in January
Vallejo, CA

Average UV index in January - Vallejo, CA
  • Average UV index in January: 3

The month with the highest UV index is June (UV index 6).
Months with the lowest UV index are January, February, November and December (UV index 3).

[Resources]

Average cloud cover in January
Vallejo, CA

Average cloud cover in January - Vallejo, CA
  • Average cloud cover in January: 35

The month with the most cloud cover is March (Cloud cover 37).
The month with the least cloud cover is July (Cloud cover 9).

[Resources]

Average visibility in January
Vallejo, CA

Average visibility in January - Vallejo, CA
  • Average visibility in January: 6mi

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

[Resources]