December weather forecastHermiston, OR
December
Weather in December
In December, winter reigns supreme in Hermiston, Oregon. The city immerses in a cold spell, with average temperatures plummeting down to the lower end of the scale. Embodying the epitome of a northern winter's charm, light snowfall visiting the city adds to the magical holiday vibes. Interesting to note, December ties with March as the rainiest month of the year, witnessing an average of 1.06" (27mm) of rainfall. So, as the year winds down in the final month, Hermiston is exceptionally draped in a serene blanket of white, offering a picturesque winter wonderland.Temperature
December is the coldest month, with the temperature often reaching an average high of 38.8°F (3.8°C) and an average low of 28.6°F (-1.9°C).Humidity
In Hermiston, the average relative humidity in December is 77%.Rainfall
The wettest months are March and December, with an average 1.06" (27mm) of rainfall.Snowfall
Months with snowfall are January through March, September, November and December. In Hermiston, in December, during 3.7 snowfall days, 1.3" (33mm) of snow is typically accumulated. Throughout the year, in Hermiston, there are 12 snowfall days, and 6.06" (154mm) of snow is accumulated.Daylight
With an average of 8h and 42min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:18 am and sunset at 4:14 pm. On the last day of December, sunrise is at 7:38 am and sunset at 4:22 pm PST.
Sunshine
January and December, with an average of 5.5h of sunshine, are months with the least sunshine.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for average individuals.Note: The UV index of 2 during December translates into the following guidance:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. To protect against the Sun's most potent rays, avoid direct exposure around midday. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Mind this! Nearly twice the UV radiation from the Sun can be reflected by the snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Hermiston, OR
- Average high temperature in December: 38.8°F
The warmest month (with the highest average high temperature) is July (88°F).
The month with the lowest average high temperature is December (38.8°F).
- Average low temperature in December: 28.6°F
The month with the highest average low temperature is August (64°F).
The coldest month (with the lowest average low temperature) is December (28.6°F).
Average pressure in December
Hermiston, OR
- Average pressure in December: 30.16"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in December
Hermiston, OR
- Average wind speed in December: 6.1mph
The windiest month (with the highest average wind speed) is April (9.2mph).
The calmest month (with the lowest average wind speed) is December (6.1mph).
Average humidity in December
Hermiston, OR
- Average humidity in December: 77%
The month with the highest relative humidity is January (79%).
The months with the lowest relative humidity are July and August (36%).
Average rainfall in December
Hermiston, OR
- Average rainfall in December: 1.06"
The wettest months (with the highest rainfall) are March and December (1.06").
The driest month (with the least rainfall) is July (0.16").
Average rainfall days in December
Hermiston, OR
- Average rainfall days in December: 12.1 days
The month with the highest number of rainy days is March (14.5 days).
The month with the least rainy days is August (3.3 days).
Average snowfall in December
Hermiston, OR
- Average snowfall in December: 1.3"
The month with the highest snowfall is February (2.72").
The months with the least snowfall are April, May, June, July, August and October (0").
Average snowfall days in December
Hermiston, OR
- Average snowfall days in December: 3.7 days
The month with the highest number of snowfall days is December (3.7 days).
The months with the least snowfall days are April, May, June, July, August and October (0 days).
Average daylight in December /
Average sunshine in December
Hermiston, OR
- Average daylight in December: 8h and 42min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in December: 5h and 30min
The month with the most sunshine is August (Average sunshine: 12h and 6min).
The months with the least sunshine are January and December (Average sunshine: 5h and 30min).
Average sunshine days in December
Hermiston, OR
- Average sunshine days in December: 16 days
The month with the most sunshine days is July (25.5 days).
The month with the least sunshine days is February (13.3 days).
Average UV index in December
Hermiston, 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, November and December (UV index 2).
Average cloud cover in December
Hermiston, OR
- Average cloud cover in December: 43
The months with the most cloud cover are January and December (Cloud cover 43).
The months with the least cloud cover are July and August (Cloud cover 9).
Average visibility in December
Hermiston, OR
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
