December weather forecastHeisson, WA
December
Weather in December
December, the first month of the winter in Heisson, is also a wintry month, with an average temperature fluctuating between 42.6°F (5.9°C) and 32.7°F (0.4°C).Temperature
Heisson witnesses the coldest weather in December, with temperatures averaging a high of 42.6°F (5.9°C) and a low of 32.7°F (0.4°C).Humidity
In December, the average relative humidity is 85%.Rainfall
In Heisson, in December, it is raining for 19 days, with typically 5.94" (151mm) of accumulated precipitation. Throughout the year, there are 177.9 rainfall days, and 40.67" (1033mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through March, November and December. In Heisson, in December, snow falls for 1.5 days, with typically accumulated 0.63" (16mm) of snow. Throughout the year, there are 9.8 snowfall days, and 7.4" (188mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 8h and 42min of daylight.On the first day of December, sunrise is at 7:31 am and sunset at 4:26 pm. On the last day of the month, sunrise is at 7:51 am and sunset at 4:35 pm PST.
Sunshine
The average sunshine in December is 3.9h.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 reading of 2, and below, represents a low health risk from unsafe exposure to UV radiation for the ordinary person.Note: In December, an average UV index of 2 transforms into the following instructions:
Although the majority can endure up to an hour in the sun without burns, children always require sun protection. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Heisson, WA
- Average high temperature in December: 42.6°F
The warmest month (with the highest average high temperature) is August (79.3°F).
The month with the lowest average high temperature is December (42.6°F).
- Average low temperature in December: 32.7°F
The month with the highest average low temperature is August (52°F).
The coldest month (with the lowest average low temperature) is December (32.7°F).
Average pressure in December
Heisson, WA
- 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
Heisson, WA
- Average wind speed in December: 5.7mph
The windiest month (with the highest average wind speed) is January (6.1mph).
The calmest month (with the lowest average wind speed) is August (3.8mph).
Average humidity in December
Heisson, WA
- Average humidity in December: 85%
The month with the highest relative humidity is February (86%).
The month with the lowest relative humidity is August (67%).
Average rainfall in December
Heisson, WA
- Average rainfall in December: 5.94"
The wettest month (with the highest rainfall) is January (6.06").
The driest month (with the least rainfall) is July (0.35").
Average rainfall days in December
Heisson, WA
- Average rainfall days in December: 19 days
The month with the highest number of rainy days is March (20.3 days).
The month with the least rainy days is August (5.1 days).
Average snowfall in December
Heisson, WA
- Average snowfall in December: 0.63"
The month with the highest snowfall is February (2.76").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Heisson, WA
- Average snowfall days in December: 1.5 days
The month with the highest number of snowfall days is February (3.7 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
Heisson, WA
- 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: 3h and 54min
The month with the most sunshine is August (Average sunshine: 10h and 48min).
The months with the least sunshine are January and February (Average sunshine: 3h and 48min).
Average sunshine days in December
Heisson, WA
- Average sunshine days in December: 10.1 days
The month with the most sunshine days is July (24.1 days).
The month with the least sunshine days is February (8.2 days).
Average UV index in December
Heisson, WA
- 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
Heisson, WA
- Average cloud cover in December: 59
The month with the most cloud cover is February (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 26).
Average visibility in December
Heisson, WA
- Average visibility in December: 5mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (5mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (5mi).





