December weather forecastVallejo, CA
December
Weather in December
The first month of the winter, December, is also a moderate month in Vallejo, California, with an average temperature ranging between min 43.2°F (6.2°C) and max 55.4°F (13°C).Temperature
The coldest time of the year is December, with temperatures averaging a high of 55.4°F (13°C) and a low of 43.2°F (6.2°C).Humidity
The average relative humidity in December is 71%.Rainfall
In Vallejo, during December, the rain falls for 8.5 days and regularly aggregates up to 0.79" (20mm) of precipitation. In Vallejo, during the entire year, the rain falls for 56.9 days and collects up to 4.88" (124mm) 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 December, sunrise is at 7:07 am and sunset at 4:49 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 4:59 pm PST.
Sunshine
December has the least sunshine of the year, with an average of 5.7h of sunshine.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 3. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for average individuals.Note: A maximum high UV index of 3 in December translates into the following recommendations:
Adopt protective measures - Suggestions to resist sunburn are offered. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Vallejo, CA
- Average high temperature in December: 55.4°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 December: 43.2°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).
Average pressure in December
Vallejo, CA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Vallejo, CA
- Average wind speed in December: 5.2mph
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).
Average humidity in December
Vallejo, CA
- Average humidity in December: 71%
The month with the highest relative humidity is March (75%).
The months with the lowest relative humidity are September and October (60%).
Average rainfall in December
Vallejo, CA
- Average rainfall in December: 0.79"
The wettest month (with the highest rainfall) is February (1.14").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in December
Vallejo, CA
- Average rainfall days in December: 8.5 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).
Average daylight in December /
Average sunshine in December
Vallejo, CA
- Average daylight in December: 9h and 36min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in December: 5h and 42min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in December
Vallejo, CA
- Average sunshine days in December: 20.8 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).
Average UV index in December
Vallejo, 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 January, February, November and December (UV index 3).
Average cloud cover in December
Vallejo, CA
- Average cloud cover in December: 36
The month with the most cloud cover is March (Cloud cover 37).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in December
Vallejo, 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).
