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
With an average high-temperature of 30.7°F (-0.7°C) and an average low-temperature of 18.5°F (-7.5°C), December is the coldest month.Humidity
In December, the average relative humidity is 86%.Rainfall
December is the month with the most rainfall in Richland. Rain falls for 8.6 days and accumulates 1.77" (45mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. The month with the most snowfall is December, when snow falls for 14.7 days and typically aggregates up to 10.59" (269mm) of snow.Daylight
With an average of 8h and 54min of daylight, December has the shortest days of the year in Richland.On the first day of December, sunrise is at 7:06 am and sunset at 4:09 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 4:18 pm PST.
Sunshine
In December, the average sunshine is 5.1h.UV index
The average daily maximum UV index in December is 2. A UV Index reading of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index of 2 during December translates into these guidelines:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized. Be cautious! The UV radiation from the Sun can be magnified almost twofold by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What month is the coldest in Richland?
How cold is December?
What is the average humidity in December?
What is the wettest month?
How many days does it rain in December?
When does it snow the most?
How many days does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Richland have in December?
When are sunrise and sunset in December in Richland?
How long on average sun shines in December?
What is the UV index reading in December?
Average temperature in December
Richland, OR
- Average high temperature in December: 30.7°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is December (30.7°F).
- Average low temperature in December: 18.5°F
The month with the highest average low temperature is August (53.8°F).
The coldest month (with the lowest average low temperature) is December (18.5°F).
Average pressure in December
Richland, OR
- Average pressure in December: 30.19"Hg
The month with the highest atmospheric pressure is January (30.22"Hg).
The month with the lowest atmospheric pressure is August (29.92"Hg).
Average wind speed in December
Richland, OR
- Average wind speed in December: 5.8mph
The windiest month (with the highest average wind speed) is April (6.2mph).
The calmest months (with the lowest average wind speed) are September and October (5.4mph).
Average humidity in December
Richland, OR
- Average humidity in December: 86%
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is August (40%).
Average rainfall in December
Richland, OR
- Average rainfall in December: 1.77"
The wettest month (with the highest rainfall) is December (1.77").
The driest month (with the least rainfall) is August (0.31").
Average rainfall days in December
Richland, OR
- Average rainfall days in December: 8.6 days
The month with the highest number of rainy days is March (15.6 days).
The month with the least rainy days is August (4.4 days).
Average snowfall in December
Richland, OR
- Average snowfall in December: 10.59"
The month with the highest snowfall is December (10.59").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Richland, OR
- Average snowfall days in December: 14.7 days
The month with the highest number of snowfall days is December (14.7 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Richland, OR
- Average daylight in December: 8h and 5min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in December: 5h and 1min
The month with the most sunshine is August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 48min).
Average sunshine days in December
Richland, OR
- Average sunshine days in December: 13.9 days
The month with the most sunshine days is July (22.7 days).
The months with the least sunshine days are February and March (11.3 days).
Average UV index in December
Richland, OR
- Average UV index in December: 2
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in December
Richland, OR
- Average cloud cover in December: 47
The month with the most cloud cover is February (Cloud cover 50).
The months with the least cloud cover are July and August (Cloud cover 9).
Average visibility in December
Richland, OR
- Average visibility in December: 4mi
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (4mi).
Richland, Oregon, USA
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