December weather forecast
San Dimas, CA

englishespañol中文
Share

Weather in December

The first month of the winter, December, is still a comfortable month in San Dimas, California, with temperature in the range of an average high of 62.4°F (16.9°C) and an average low of 45.5°F (7.5°C).

Temperature

December, with its average high-temperature of 62.4°F (16.9°C) and an average low-temperature of 45.5°F (7.5°C), holds the record as the coldest month.

Humidity

In San Dimas, California, the average relative humidity in December is 51%.

Rainfall

In San Dimas, in December, it is raining for 5.7 days, with typically 1.3" (33mm) of accumulated precipitation. Throughout the year, in San Dimas, California, there are 45.2 rainfall days, and 6.5" (165mm) of precipitation is accumulated.

Daylight

With an average of 9h and 54min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 6:39 am and sunset at 4:41 pm. On the last day of December, sunrise is at 6:56 am and sunset at 4:52 pm PST.

Sunshine

January, February and December, with an average of 7h of sunshine, are months with the least sunshine in San Dimas.

UV index

With an average maximum UV index of 3, December is the month with the lowest UV index in San Dimas, California. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for average individuals.
Note: In December, the maximum UV index of 3 suggests this advice:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.
[Resources]

Frequently asked questions

What is the coldest month in San Dimas?

With average high temperatures of 62.4°F (16.9°C) and lows of 45.5°F (7.5°C), December is the coldest month.

What is the usual temperature for San Dimas in December?

December temperatures vary between a high-temperature of 62.4°F (16.9°C) and a low-temperature of 45.5°F (7.5°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), which calculates the temperature value influenced by the moisture in the air, in September is calculated to be 87.8°F (31°C).

What is the average humidity in December in San Dimas?

The average relative humidity in December is 51%.

How much does it rain in San Dimas in December?

In San Dimas, during December, the rain falls for 5.7 days and regularly aggregates up to 1.3" (33mm) of precipitation.

What is the month with the shortest days in San Dimas?

December has the shortest days of the year, with an average of 9h and 54min of daylight.

How many hours of daylight does San Dimas have in December?

In December, the average day length in San Dimas is 9h and 56min.

When is the sunrise / sunset in December in San Dimas?

On the first day of December in San Dimas, sunrise is at 6:39 am and sunset at 4:41 pm. On the last day of the month, sunrise is at 6:56 am and sunset at 4:52 pm PST.

What are the months with the least sunshine in San Dimas?

January, February and December, with an average of 7h of sunshine, are months with the least sunshine in San Dimas.

How many hours of sunshine does San Dimas have in December?

In December, the average sunshine duration is 7h.

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

December is the month with the lowest UV index in San Dimas, California, with an average maximum UV index of 3.

What is the UV index reading in December in San Dimas?

In December, the average daily maximum UV index in San Dimas is 3. A UV Index value of 3 to 5 symbolizes a medium health risk from unsafe exposure to Sun's UV rays.
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 Dimas, CA

Average temperature in December - San Dimas, CA
  • Average high temperature in December: 62.4°F

The warmest month (with the highest average high temperature) is August (89.4°F).
The month with the lowest average high temperature is December (62.4°F).

  • Average low temperature in December: 45.5°F

The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is December (45.5°F).

[Resources]

Average pressure in December
San Dimas, CA

Average pressure in December - San Dimas, CA
  • Average pressure in December: 30.07"Hg

The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).

[Resources]

Average wind speed in December
San Dimas, CA

Average wind speed in December - San Dimas, CA
  • Average wind speed in December: 5.1mph

The windiest months (with the highest average wind speed) are April and May (5.7mph).
The calmest month (with the lowest average wind speed) is September (4.3mph).

[Resources]

Average humidity in December
San Dimas, CA

Average humidity in December - San Dimas, CA
  • Average humidity in December: 51%

The months with the highest relative humidity are March and May (55%).
The months with the lowest relative humidity are August and November (45%).

[Resources]

Average rainfall in December
San Dimas, CA

Average rainfall in December - San Dimas, CA
  • Average rainfall in December: 1.3"

The wettest month (with the highest rainfall) is February (1.46").
The driest month (with the least rainfall) is June (0.04").

[Resources]

Average rainfall days in December
San Dimas, CA

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

The month with the highest number of rainy days is March (6.3 days).
The month with the least rainy days is June (1.2 days).

[Resources]

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

Average daylight in December / Average sunshine in December - San Dimas, CA
  • Average daylight in December: 9h and 5min

The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).

  • Average sunshine in December: 7h and 0min

The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The months with the least sunshine are January, February and December (Average sunshine: 7h and 0min).

[Resources]

Average sunshine days in December
San Dimas, CA

Average sunshine days in December - San Dimas, CA
  • Average sunshine days in December: 23.8 days

The month with the most sunshine days is June (27.8 days).
The month with the least sunshine days is February (22 days).

[Resources]

Average UV index in December
San Dimas, CA

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

The months with the highest UV index are July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).

[Resources]

Average cloud cover in December
San Dimas, CA

Average cloud cover in December - San Dimas, CA
  • Average cloud cover in December: 21

The months with the most cloud cover are March and December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 5).

[Resources]

Average visibility in December
San Dimas, CA

Average visibility in December - San Dimas, 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).

[Resources]

San Dimas, California, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location