December weather forecastGromore, WA
December
Weather in December
The first month of the winter, December, is still a cold month in Gromore, Washington, with an average temperature ranging between max 36.9°F (2.7°C) and min 25.5°F (-3.6°C).Temperature
December is the coldest month, exhibiting average temperatures of 36.9°F (2.7°C) at the peak and 25.5°F (-3.6°C) at the base.Humidity
The average relative humidity in December is 80%.Rainfall
In Gromore, during December, the rain falls for 9.1 days and regularly aggregates up to 0.83" (21mm) of precipitation. Throughout the year, there are 82.2 rainfall days, and 5.43" (138mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through March, September, November and December. December is the month with the most snowfall. Snow falls for 5.4 days and accumulates 2.76" (70mm) of snow.Daylight
The month with the shortest days is December, with an average of 8h and 36min of daylight.On the first day of the month, sunrise is at 7:27 am and sunset at 4:17 pm. On the last day of December, in Gromore, sunrise is at 7:46 am and sunset at 4:25 pm PST.
Sunshine
In December, the average sunshine is 5.9h.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 estimate of 2, and below, represents a minimal health vulnerability from unsafe exposure to UV radiation for average individuals.Note: During December, 2 as the daily maximum UV index converts into the following advice:
Those with sensitive skin, infants, and children require constant safeguarding from prolonged sun exposure. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses. Take to heart! Snow reflection can almost magnify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Gromore, WA
- Average high temperature in December: 36.9°F
The warmest month (with the highest average high temperature) is August (86.5°F).
The month with the lowest average high temperature is December (36.9°F).
- Average low temperature in December: 25.5°F
The month with the highest average low temperature is August (60.3°F).
The coldest month (with the lowest average low temperature) is December (25.5°F).
Average pressure in December
Gromore, WA
- Average pressure in December: 30.14"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is August (29.93"Hg).
Average wind speed in December
Gromore, WA
- Average wind speed in December: 4.4mph
The windiest month (with the highest average wind speed) is June (7.1mph).
The calmest month (with the lowest average wind speed) is December (4.4mph).
Average humidity in December
Gromore, WA
- Average humidity in December: 80%
The month with the highest relative humidity is January (81%).
The months with the lowest relative humidity are July and August (39%).
Average rainfall in December
Gromore, WA
- Average rainfall in December: 0.83"
The wettest month (with the highest rainfall) is January (0.87").
The driest month (with the least rainfall) is July (0.08").
Average rainfall days in December
Gromore, WA
- Average rainfall days in December: 9.1 days
The month with the highest number of rainy days is March (10.8 days).
The month with the least rainy days is August (2 days).
Average snowfall in December
Gromore, WA
- Average snowfall in December: 2.76"
The month with the highest snowfall is December (2.76").
The months with the least snowfall are April, May, June, July, August and October (0").
Average snowfall days in December
Gromore, WA
- Average snowfall days in December: 5.4 days
The month with the highest number of snowfall days is December (5.4 days).
The months with the least snowfall days are May, June, July, August and October (0 days).
Average daylight in December /
Average sunshine in December
Gromore, WA
- Average daylight in December: 8h and 36min
The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).
- Average sunshine in December: 5h and 54min
The months with the most sunshine are July and August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 5h and 36min).
Average sunshine days in December
Gromore, WA
- Average sunshine days in December: 17.3 days
The month with the most sunshine days is July (27.5 days).
The month with the least sunshine days is February (15.8 days).
Average UV index in December
Gromore, WA
- 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
Gromore, WA
- Average cloud cover in December: 37
The month with the most cloud cover is January (Cloud cover 40).
The months with the least cloud cover are July and August (Cloud cover 9).
Average visibility in December
Gromore, WA
- Average visibility in December: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).





