December weather forecast
Pomona, CA

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Trails in the rural mountainous region of Pomona, California, with scenic slopes and dense population down below
Trails in the rural mountainous region of Pomona, California, with scenic slopes and dense population down below

Weather in December

December in Pomona marks the height of the winter season. The dramatic drop in temperature from the fall season is a clear indicator that winter has taken hold. With the decrease of sunshine duration, cloudier days become more prevalent giving the city a touch of grey. Despite the drop to a lower UV index, chillier afternoons remind everyone to pack their winter wear. The last month of the year wraps Pomona in a cool wintery embrace, providing a beautiful finish to the city’s weather cycle.

Temperature

December, known for its average high temperature of 63.1°F (17.3°C) and an average low temperature of 46.8°F (8.2°C), is the coldest month.

Humidity

In December, the average relative humidity in Pomona is 51%.

Rainfall

The wettest months in Pomona are February and December, with an average 1.65" (42mm) of rainfall.

Snowfall

In Pomona, snow does not fall in January, March through December.

Daylight

The month with the shortest days in Pomona, California, is December, with an average of 9h and 54min of daylight.
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

The months with the least sunshine in Pomona, California, are February and December, with an average of 6.9h of sunshine.

UV index

January, February, November and December, with an average maximum UV index of 4, are months with the lowest UV index. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.
Note: A daily maximum UV index of 4 in December translates into the following instructions:
Take heed. Individuals of lighter complexion can be burned in less than half an hour. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.

Frequently asked questions

What month is the coldest in Pomona?

With average temperatures fluctuating between a high of 63.1°F (17.3°C) and a low of 46.8°F (8.2°C), December stands out as the coldest month in Pomona.

What are the temperatures in Pomona in December?

The high-temperature during December is 63.1°F (17.3°C) and the low-temperature is 46.8°F (8.2°C). The average heat index (a.k.a. 'real feel', 'felt air temperature'), which represents the influence of relative humidity on air temperature, in September is evaluated at 89.6°F (32°C).

What is the average humidity in December in Pomona?

The average relative humidity in December in Pomona, California, is 51%.

What is the wettest month in Pomona?

The wettest months in Pomona are February and December, with an average 1.65" (42mm) of rainfall.

How much does it rain in Pomona in December?

In December, the rain falls for 5.8 days. Throughout December, 1.65" (42mm) of precipitation is accumulated.

When it does not snow in Pomona?

January, March through December are months without snowfall.

What is the month with the shortest days in Pomona?

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

What is the average length of the day in December in Pomona?

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

What time are sunrise and sunset in December in Pomona?

In December, on the first day of the month, 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 is the month with the least sunshine in Pomona?

February and December, with an average of 6.9h of sunshine, are months with the least sunshine.

How many hours of sunshine does Pomona have in December?

The average sunshine duration in December is 6.9h.

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

The months with the lowest UV index in Pomona are January, February, November and December, with an average maximum UV index of 4.

What is the UV index reading in December in Pomona?

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

Average temperature in December
Pomona, CA

Average temperature in December - Pomona, CA
  • Average high temperature in December: 63.1°F

The warmest month (with the highest average high temperature) is August (90.1°F).
The month with the lowest average high temperature is December (63.1°F).

  • Average low temperature in December: 46.8°F

The month with the highest average low temperature is August (65.7°F).
The coldest months (with the lowest average low temperature) are February and December (46.8°F).

Average pressure in December
Pomona, CA

Average pressure in December - Pomona, 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).

Average wind speed in December
Pomona, CA

Average wind speed in December - Pomona, CA
  • Average wind speed in December: 5mph

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 (4.4mph).

Average humidity in December
Pomona, CA

Average humidity in December - Pomona, CA
  • Average humidity in December: 51%

The month with the highest relative humidity is May (56%).
The months with the lowest relative humidity are August and November (45%).

Average rainfall in December
Pomona, CA

Average rainfall in December - Pomona, CA
  • Average rainfall in December: 1.65"

The wettest months (with the highest rainfall) are February and December (1.65").
The driest months (with the least rainfall) are June and August (0.04").

Average rainfall days in December
Pomona, CA

Average rainfall days in December - Pomona, CA
  • Average rainfall days in December: 5.8 days

The month with the highest number of rainy days is March (7.6 days).
The month with the least rainy days is June (0.8 days).

Average snowfall days in December
Pomona, CA

Average snowfall days in December - Pomona, CA
  • Average snowfall days in December: 0 days

The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).

Average daylight in December /
Average sunshine in December
Pomona, CA

Average daylight in December / Average sunshine in December - Pomona, 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: 6h and 5min

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 54min).

Average sunshine days in December
Pomona, CA

Average sunshine days in December - Pomona, CA
  • Average sunshine days in December: 23.7 days

The month with the most sunshine days is June (28.7 days).
The month with the least sunshine days is February (21.1 days).

Average UV index in December
Pomona, CA

Average UV index in December - Pomona, CA
  • Average UV index in December: 4

The month with the highest UV index is August (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 4).

Average cloud cover in December
Pomona, CA

Average cloud cover in December - Pomona, CA
  • Average cloud cover in December: 21

The months with the most cloud cover are February, March and December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 4).

Average visibility in December
Pomona, CA

Average visibility in December - Pomona, 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).

Pomona, California, USA

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