December weather forecast
San Joaquin, CA

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Weather in December

The first month of the winter, December, is still a refreshing month in San Joaquin, California, with an average temperature ranging between max 56.5°F (13.6°C) and min 42.6°F (5.9°C).

Temperature

San Joaquin experiences its lowest temperatures in December, with an average peak of 56.5°F (13.6°C) and a low of 42.6°F (5.9°C).

Humidity

January and December, with an average relative humidity of 66%, are the most humid months.

Rainfall

In San Joaquin, in December, it is raining for 5.7 days, with typically 0.35" (9mm) of accumulated precipitation. Throughout the year, there are 37.2 rainfall days, and 2.48" (63mm) of precipitation is accumulated.

Daylight

December has the shortest days of the year, with an average of 9h and 42min of daylight.
On the first day of the month, sunrise is at 6:55 am and sunset at 4:45 pm. On the last day of December, sunrise is at 7:12 am and sunset at 4:55 pm PST.

Sunshine

The months with the least sunshine are February and December, with an average of 6.4h of sunshine.

UV index

The months with the lowest UV index are January, November and December, with an average maximum UV index of 3. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for average individuals.
Note: In December, the maximum UV index of 3 translates into these guidelines:
Be mindful. Individuals with a lighter skin tone may suffer burns in less than 30 minutes. Avoiding the Sun during its peak radiation time around midday is a healthy practice. 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.
Updated: Aug 25, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the coldest month?

San Joaquin's coldest weather arrives in December, when temperatures average a high of 56.5°F (13.6°C) and a low of 42.6°F (5.9°C).

What is the average December temperature?

In San Joaquin, 56.5°F (13.6°C) is the average high-temperature and 42.6°F (5.9°C) is the average low-temperature during December. In May, the average heat index (a.k.a. 'feels like', 'felt air temperature'), which combines air temperature and relative humidity, is estimated at 82.4°F (28°C).

What are the most humid months?

January and December, with an average relative humidity of 66%, are most humid months.

What is the average humidity in December?

In December, the average relative humidity is 66%.

How much does it rain in December?

In December, the rain falls for 5.7 days. Throughout December, 0.35" (9mm) of precipitation is accumulated.

What is the month with the shortest days?

The month with the shortest days in San Joaquin is December, with an average of 9h and 42min of daylight.

What is the average length of the day in December?

In San Joaquin, the average day length in December is 9h and 43min.

When is the sunrise / sunset in December?

On the first day of December, sunrise is at 6:55 am and sunset at 4:45 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 4:55 pm PST.

What is the month with the least sunshine?

The months with the least sunshine are February and December, with an average of 6.4h of sunshine.

How long on average sun shines in December?

The average sunshine duration in December is 6.4h.

What is the month with the lowest UV index in San Joaquin?

January, November and December, with an average maximum UV index of 3, are months with the lowest UV index in San Joaquin.

How high is the UV index in December?

In December, the average daily maximum UV index is 3. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from exposure to the Sun's 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 December
San Joaquin, CA

Average temperature in December - San Joaquin, CA
  • Average high temperature in December: 56.5°F

The warmest month (with the highest average high temperature) is July (100.9°F).
The month with the lowest average high temperature is December (56.5°F).

  • Average low temperature in December: 42.6°F

The month with the highest average low temperature is July (67.1°F).
The coldest month (with the lowest average low temperature) is December (42.6°F).

Average pressure in December
San Joaquin, CA

Average pressure in December - San Joaquin, CA
  • Average pressure in December: 30.12"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in December
San Joaquin, CA

Average wind speed in December - San Joaquin, CA
  • Average wind speed in December: 5.3mph

The windiest month (with the highest average wind speed) is June (7.6mph).
The calmest month (with the lowest average wind speed) is January (5.1mph).

Average humidity in December
San Joaquin, CA

Average humidity in December - San Joaquin, CA
  • Average humidity in December: 66%

The months with the highest relative humidity are January and December (66%).
The month with the lowest relative humidity is July (30%).

Average rainfall in December
San Joaquin, CA

Average rainfall in December - San Joaquin, CA
  • Average rainfall in December: 0.35"

The wettest months (with the highest rainfall) are February and March (0.43").
The driest months (with the least rainfall) are June, July, August and September (0.04").

Average rainfall days in December
San Joaquin, CA

Average rainfall days in December - San Joaquin, CA
  • Average rainfall days in December: 5.7 days

The month with the highest number of rainy days is March (7 days).
The months with the least rainy days are August and September (0.5 days).

Average daylight in December /
Average sunshine in December
San Joaquin, CA

Average daylight in December / Average sunshine in December - San Joaquin, CA
  • Average daylight in December: 9h and 4min

The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 42min).

  • Average sunshine in December: 6h and 2min

The month with the most sunshine is July (Average sunshine: 12h and 12min).
The months with the least sunshine are February and December (Average sunshine: 6h and 24min).

Average sunshine days in December
San Joaquin, CA

Average sunshine days in December - San Joaquin, CA
  • Average sunshine days in December: 24.6 days

The month with the most sunshine days is August (29.7 days).
The month with the least sunshine days is February (22 days).

Average UV index in December
San Joaquin, CA

Average UV index in December - San Joaquin, CA
  • Average UV index in December: 3

The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are January, November and December (UV index 3).

Average cloud cover in December
San Joaquin, CA

Average cloud cover in December - San Joaquin, CA
  • Average cloud cover in December: 28

The month with the most cloud cover is March (Cloud cover 29).
The months with the least cloud cover are July and August (Cloud cover 4).

Average visibility in December
San Joaquin, CA

Average visibility in December - San Joaquin, 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).

San Joaquin, California, USA

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