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
The coldest month is December, with an average high-temperature of 31.8°F (-0.1°C) and an average low-temperature of 19.4°F (-7°C).Humidity
In December, the average relative humidity is 83%.Rainfall
The month with the most rainfall in Riverside is December, when the rain falls for 9.3 days and typically aggregates up to 1.77" (45mm) of precipitation.Snowfall
January through May, November and December are months with snowfall. December is the month with the most snowfall. Snow falls for 13.1 days and accumulates 9.13" (232mm) of snow.Daylight
With an average of 9h and 0min of daylight, December has the shortest days of the year in Riverside.On the first day of the month, sunrise is at 8:06 am and sunset at 5:17 pm. On the last day of December, sunrise is at 8:25 am and sunset at 5:26 pm MST.
Sunshine
December has the least sunshine of the year, with an average of 5.1h of sunshine.UV index
The months with the lowest UV index in Riverside are January through March, November and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV radiation for the ordinary person.Note: A daily maximum UV index of 2 in December translates into the following instructions:
Despite the majority tolerating prolonged sun exposure, those with sensitive skin, infants, and children demand continual protection. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. Enhance your sun protection with tightly woven, yet airy clothing. Notice! The UV radiation of the Sun can be intensified nearly twofold due to the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What part of the year is the coldest?
How cold is it in December?
What is the average humidity in December in Riverside?
What is the rainiest month?
How much does it rain in December?
When does it snow the most?
How much does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Riverside have in December?
What time are sunrise and sunset in December?
What is the month with the least sunshine?
How long on average sun shines in December?
When is the lowest UV index?
How high is the UV index in December?
Average temperature in December
Riverside, OR
- Average high temperature in December: 31.8°F
The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is December (31.8°F).
- Average low temperature in December: 19.4°F
The month with the highest average low temperature is August (59°F).
The coldest month (with the lowest average low temperature) is January (19.2°F).
Average pressure in December
Riverside, OR
- Average pressure in December: 30.2"Hg
The month with the highest atmospheric pressure is January (30.23"Hg).
The months with the lowest atmospheric pressure are June and August (29.93"Hg).
Average wind speed in December
Riverside, OR
- Average wind speed in December: 5.4mph
The windiest month (with the highest average wind speed) is April (7.8mph).
The calmest month (with the lowest average wind speed) is January (5mph).
Average humidity in December
Riverside, OR
- Average humidity in December: 83%
The month with the highest relative humidity is January (85%).
The months with the lowest relative humidity are July and August (31%).
Average rainfall in December
Riverside, 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 July (0.12").
Average rainfall days in December
Riverside, OR
- Average rainfall days in December: 9.3 days
The month with the highest number of rainy days is March (15.3 days).
The month with the least rainy days is July (3.4 days).
Average snowfall in December
Riverside, OR
- Average snowfall in December: 9.13"
The month with the highest snowfall is December (9.13").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Riverside, OR
- Average snowfall days in December: 13.1 days
The month with the highest number of snowfall days is December (13.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Riverside, OR
- Average daylight in December: 9h and 0min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in December: 5h and 1min
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 6min).
Average sunshine days in December
Riverside, OR
- Average sunshine days in December: 14.8 days
The month with the most sunshine days is July (25.3 days).
The month with the least sunshine days is March (11.5 days).
Average UV index in December
Riverside, OR
- Average UV index in December: 2
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in December
Riverside, OR
- Average cloud cover in December: 47
The months with the most cloud cover are January and December (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 8).
Average visibility in December
Riverside, OR
- Average visibility in December: 5mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The month with the lowest visibility is January (4mi).
Riverside, Oregon, USA
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