December weather forecastUpper Lake, CA
December
Weather in December
December, the first month of the winter in Upper Lake, is also a fresh month, with temperature in the range of an average high of 52.3°F (11.3°C) and an average low of 37.2°F (2.9°C).Temperature
December, with its average high-temperature of 52.3°F (11.3°C) and an average low-temperature of 37.2°F (2.9°C), holds the record as the coldest month.Humidity
The average relative humidity in December is 73%.Rainfall
In Upper Lake, in December, it is raining for 12.3 days, with typically 3.7" (94mm) of accumulated precipitation. In Upper Lake, California, during the entire year, the rain falls for 92 days and collects up to 21.02" (534mm) of precipitation.Snowfall
Months with snowfall in Upper Lake, California, are January through March, November and December. In December, it is snowing for 0.2 days. Throughout December, 0.08" (2mm) of snow is accumulated. In Upper Lake, during the entire year, snow falls for 2 days and aggregates up to 1.34" (34mm) of snow.Daylight
December has the shortest days of the year in Upper Lake, with an average of 9h and 30min of daylight.On the first day of the month, sunrise is at 7:12 am and sunset at 4:49 pm. On the last day of December, sunrise is at 7:30 am and sunset at 4:59 pm PST.
Sunshine
December has the least sunshine of the year, with an average of 5.3h of sunshine.UV index
January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for the ordinary person.Note: During December, 3 as the daily maximum UV index converts into the following advice:
Heed the precautions - Suggestions to avoid sunburn are made. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Employ a wide-brim hat for potent defense against up to 50% of UV rays. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Upper Lake, CA
- Average high temperature in December: 52.3°F
The warmest month (with the highest average high temperature) is July (89.6°F).
The month with the lowest average high temperature is December (52.3°F).
- Average low temperature in December: 37.2°F
The month with the highest average low temperature is July (57.7°F).
The coldest month (with the lowest average low temperature) is December (37.2°F).
Average pressure in December
Upper Lake, CA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are June and August (29.91"Hg).
Average wind speed in December
Upper Lake, CA
- Average wind speed in December: 4.4mph
The windiest month (with the highest average wind speed) is April (5.3mph).
The calmest month (with the lowest average wind speed) is November (4.1mph).
Average humidity in December
Upper Lake, CA
- Average humidity in December: 73%
The month with the highest relative humidity is March (75%).
The month with the lowest relative humidity is July (47%).
Average rainfall in December
Upper Lake, CA
- Average rainfall in December: 3.7"
The wettest month (with the highest rainfall) is February (4.06").
The driest month (with the least rainfall) is July (0.04").
Average rainfall days in December
Upper Lake, CA
- Average rainfall days in December: 12.3 days
The month with the highest number of rainy days is March (15.9 days).
The months with the least rainy days are July and August (1.3 days).
Average snowfall in December
Upper Lake, CA
- Average snowfall in December: 0.08"
The months with the highest snowfall are January and February (0.47").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Upper Lake, CA
- Average snowfall days in December: 0.2 days
The month with the highest number of snowfall days is February (0.9 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Upper Lake, CA
- Average daylight in December: 9h and 30min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in December: 5h and 18min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in December
Upper Lake, CA
- Average sunshine days in December: 17.6 days
The months with the most sunshine days are July and August (28.3 days).
The month with the least sunshine days is March (13.7 days).
Average UV index in December
Upper Lake, CA
- Average UV index in December: 3
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in December
Upper Lake, CA
- Average cloud cover in December: 42
The month with the most cloud cover is March (Cloud cover 44).
The months with the least cloud cover are July and August (Cloud cover 5).
Average visibility in December
Upper Lake, CA
- Average visibility in December: 5mi
The months with the highest visibility are January, February, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are March and December (5mi).





