December weather forecastPomona, CA
December
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.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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: 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: 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: 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: 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: 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: 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: 9h and 54min
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 54min
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: 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: 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: 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: 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).
