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 time of the year is December, with temperatures averaging a high of 44.4°F (6.9°C) and a low of 34.7°F (1.5°C).Humidity
In December, the average relative humidity in Happy Valley, Oregon, is 83%.Rainfall
December is the month with the most rainfall. Rain falls for 18.5 days and accumulates 4.57" (116mm) of precipitation.Snowfall
January through March, November and December are months with snowfall. In December, in Happy Valley, Oregon, it is snowing for 0.8 days. Throughout December, 0.39" (10mm) of snow is accumulated. Throughout the year, there are 6.5 snowfall days, and 4.13" (105mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 8h and 48min of daylight.On the first day of the month, sunrise is at 7:30 am and sunset at 4:28 pm. On the last day of December, in Happy Valley, sunrise is at 7:49 am and sunset at 4:37 pm PST.
Sunshine
In December, the average sunshine is 4.4h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Happy Valley. A UV Index estimate of 2, and below, represents a minimal health hazard from unsafe exposure to UV radiation for the average person.Note: The maximum UV index of 2 during December leads to these instructions:
Those with sensitive skin, infants, and children require constant safeguarding from prolonged sun exposure. Around midday, solar radiation is most harmful; hence, exposure should be limited. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation. Alert! The snow's reflection can amplify the UV radiation of the Sun nearly twice.
Frequently asked questions
What is the coldest month in Happy Valley?
How cold is December in Happy Valley?
What is the average humidity in December in Happy Valley?
What is the rainiest month in Happy Valley?
How many days does it rain in December in Happy Valley?
How many days does it snow in December in Happy Valley?
What is the month with the shortest days in Happy Valley?
How many hours of daylight does Happy Valley have in December?
When is the sunrise / sunset in December in Happy Valley?
How long on average sun shines in December in Happy Valley?
When is the lowest UV index in Happy Valley?
What is the UV index reading in December in Happy Valley?
Average temperature in December
Happy Valley, OR
- Average high temperature in December: 44.4°F
The warmest month (with the highest average high temperature) is August (81.7°F).
The month with the lowest average high temperature is December (44.4°F).
- Average low temperature in December: 34.7°F
The month with the highest average low temperature is August (54.5°F).
The coldest month (with the lowest average low temperature) is December (34.7°F).
Average pressure in December
Happy Valley, OR
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed in December
Happy Valley, OR
- Average wind speed in December: 5.7mph
The windiest month (with the highest average wind speed) is January (6mph).
The calmest month (with the lowest average wind speed) is August (3.7mph).
Average humidity in December
Happy Valley, OR
- Average humidity in December: 83%
The month with the highest relative humidity is February (84%).
The month with the lowest relative humidity is August (63%).
Average rainfall in December
Happy Valley, OR
- Average rainfall in December: 4.57"
The wettest month (with the highest rainfall) is December (4.57").
The driest month (with the least rainfall) is July (0.31").
Average rainfall days in December
Happy Valley, OR
- Average rainfall days in December: 18.5 days
The month with the highest number of rainy days is March (20.4 days).
The month with the least rainy days is July (4.8 days).
Average snowfall in December
Happy Valley, OR
- Average snowfall in December: 0.39"
The month with the highest snowfall is March (1.46").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Happy Valley, OR
- Average snowfall days in December: 0.8 days
The month with the highest number of snowfall days is February (2.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Happy Valley, OR
- Average daylight in December: 8h and 5min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in December: 4h and 2min
The month with the most sunshine is August (Average sunshine: 11h and 0min).
The month with the least sunshine is February (Average sunshine: 4h and 12min).
Average sunshine days in December
Happy Valley, OR
- Average sunshine days in December: 10.9 days
The month with the most sunshine days is July (23.9 days).
The month with the least sunshine days is February (8.3 days).
Average UV index in December
Happy Valley, OR
- 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
Happy Valley, OR
- Average cloud cover in December: 55
The month with the most cloud cover is February (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 22).
Average visibility in December
Happy Valley, OR
- Average visibility in December: 5mi
The months with the highest visibility are July, August, September and October (6mi).
The months with the lowest visibility are January, February, March, April, May, June, November and December (5mi).
Happy Valley, Oregon, USA
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