December weather forecastSpring Valley, CA
December
Weather in December
The first month of the winter, December, is still a comfortable month in Spring Valley, California, with temperature in the range of an average low of 49.3°F (9.6°C) and an average high of 64.4°F (18°C).Temperature
The coldest period tends to be December, when average temperatures fluctuate between a high of 64.4°F (18°C) and a low of 49.3°F (9.6°C).Humidity
In December, the average relative humidity is 59%.Rainfall
In Spring Valley, in December, it is raining for 3.5 days, with typically 0.51" (13mm) of accumulated precipitation. Throughout the year, there are 33 rainfall days, and 2.52" (64mm) of precipitation is accumulated.Daylight
The month with the shortest days is December, with an average of 10h and 0min of daylight.On the first day of the month, sunrise is at 6:32 am and sunset at 4:41 pm. On the last day of December, sunrise is at 6:50 am and sunset at 4:52 pm PST.
Sunshine
February and December, with an average of 6.7h of sunshine, are months with the least sunshine in Spring Valley.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 of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum UV index, 4 during December, leads to the following recommendations:
Act with care - The need to guard against sun damage is communicated. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Spring Valley, CA
- Average high temperature in December: 64.4°F
The warmest month (with the highest average high temperature) is August (82.9°F).
The month with the lowest average high temperature is December (64.4°F).
- Average low temperature in December: 49.3°F
The month with the highest average low temperature is August (65.8°F).
The coldest month (with the lowest average low temperature) is February (48.7°F).
Average pressure in December
Spring Valley, CA
- Average pressure in December: 30.06"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in December
Spring Valley, CA
- Average wind speed in December: 5mph
The windiest month (with the highest average wind speed) is April (5.6mph).
The calmest month (with the lowest average wind speed) is October (4.5mph).
Average humidity in December
Spring Valley, CA
- Average humidity in December: 59%
The month with the highest relative humidity is May (67%).
The month with the lowest relative humidity is November (54%).
Average rainfall in December
Spring Valley, CA
- Average rainfall in December: 0.51"
The wettest month (with the highest rainfall) is February (0.55").
The driest months (with the least rainfall) are June, July and October (0.04").
Average rainfall days in December
Spring Valley, CA
- Average rainfall days in December: 3.5 days
The month with the highest number of rainy days is March (5.3 days).
The month with the least rainy days is June (0.8 days).
Average daylight in December /
Average sunshine in December
Spring Valley, CA
- Average daylight in December: 10h and 0min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in December: 6h and 42min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The months with the least sunshine are February and December (Average sunshine: 6h and 42min).
Average sunshine days in December
Spring Valley, CA
- Average sunshine days in December: 26.7 days
The month with the most sunshine days is October (28.9 days).
The month with the least sunshine days is February (23.4 days).
Average UV index in December
Spring Valley, CA
- Average UV index in December: 4
The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 4).
Average cloud cover in December
Spring Valley, CA
- Average cloud cover in December: 24
The months with the most cloud cover are March and December (Cloud cover 24).
The month with the least cloud cover is August (Cloud cover 7).
Average visibility in December
Spring Valley, 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).
