Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
During the coldest month, December, temperatures average a high of 45°F (7.2°C) and a low of 30°F (-1.1°C).Humidity
The average relative humidity in December is 81%.Rainfall
The month with the most rainfall is December, when the rain falls for 14.5 days and typically aggregates up to 6.14" (156mm) of precipitation.Snowfall
January through April, November and December are months with snowfall. In Lewiston, in December, during 4.3 snowfall days, 5.43" (138mm) of snow is typically accumulated. Throughout the year, there are 21.6 snowfall days, and 28.46" (723mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 18min of daylight.On the first day of December, sunrise is at 7:16 am and sunset at 4:44 pm. On the last day of the month, sunrise is at 7:35 am and sunset at 4:54 pm PST.
Sunshine
December has the least sunshine of the year, with an average of 4.6h of sunshine.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV rays for the ordinary person.Note: The maximum UV index of 2 during December translates into these guidelines:
Children necessitate constant protection from sunlight, unlike the majority, who can remain under the sun for about an hour without burning. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Forewarned is forearmed! The Sun's UV radiation can be almost doubled in intensity by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the coldest months?
What are the temperatures in December?
What is the average humidity in December?
What is the rainiest month?
How much does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
What time are sunrise and sunset in December?
What is the month with the least sunshine?
How many hours of sunshine does Lewiston have in December?
When is the lowest UV index?
How high is the UV index in December?
Average temperature in December
Lewiston, CA
- Average high temperature in December: 45°F
The warmest months (with the highest average high temperature) are July and August (84.6°F).
The month with the lowest average high temperature is December (45°F).
- Average low temperature in December: 30°F
The month with the highest average low temperature is July (51.3°F).
The coldest month (with the lowest average low temperature) is December (30°F).
Average pressure in December
Lewiston, CA
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is August (29.94"Hg).
Average wind speed in December
Lewiston, CA
- Average wind speed in December: 4.2mph
The windiest months (with the highest average wind speed) are March and April (4.8mph).
The calmest month (with the lowest average wind speed) is August (3.4mph).
Average humidity in December
Lewiston, CA
- Average humidity in December: 81%
The month with the highest relative humidity is March (82%).
The month with the lowest relative humidity is August (54%).
Average rainfall in December
Lewiston, CA
- Average rainfall in December: 6.14"
The wettest month (with the highest rainfall) is December (6.14").
The driest months (with the least rainfall) are July and August (0.16").
Average rainfall days in December
Lewiston, CA
- Average rainfall days in December: 14.5 days
The month with the highest number of rainy days is March (18.3 days).
The month with the least rainy days is August (2.5 days).
Average snowfall in December
Lewiston, CA
- Average snowfall in December: 5.43"
The month with the highest snowfall is February (8.35").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Lewiston, CA
- Average snowfall days in December: 4.3 days
The month with the highest number of snowfall days is February (5.3 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Lewiston, CA
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in December: 4h and 4min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 4h and 36min).
Average sunshine days in December
Lewiston, CA
- Average sunshine days in December: 13.3 days
The month with the most sunshine days is August (26.8 days).
The month with the least sunshine days is March (10.6 days).
Average UV index in December
Lewiston, CA
- Average UV index in December: 2
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Lewiston, CA
- Average cloud cover in December: 52
The month with the most cloud cover is March (Cloud cover 54).
The month with the least cloud cover is August (Cloud cover 8).
Average visibility in December
Lewiston, CA
- Average visibility in December: 4mi
The months with the highest visibility are June, July, August, September and October (6mi).
The months with the lowest visibility are March and December (4mi).
Lewiston, California, USA
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