December weather forecastSaint John, WA
December
Weather in December
December, the first month of the winter in Saint John, is still a cold month, with temperature in the range of an average low of 23.9°F (-4.5°C) and an average high of 33.1°F (0.6°C).Temperature
With an average high-temperature of 33.1°F (0.6°C) and an average low-temperature of 23.9°F (-4.5°C), December is the coldest month.Humidity
The average relative humidity in December is 85%.Rainfall
In Saint John, during December, the rain falls for 6.5 days and regularly aggregates up to 0.79" (20mm) of precipitation. In Saint John, Washington, during the entire year, the rain falls for 84.3 days and collects up to 7.24" (184mm) of precipitation.Snowfall
January through May, September, November and December are months with snowfall. In Saint John, Washington, in December, snow falls for 9.3 days, with typically accumulated 2.91" (74mm) of snow. Throughout the year, there are 32.5 snowfall days, and 14.09" (358mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 8h and 36min of daylight.On the first day of December, sunrise is at 7:16 am and sunset at 4:02 pm. On the last day of the month, sunrise is at 7:36 am and sunset at 4:11 pm PST.
Sunshine
December has the least sunshine of the year in Saint John, with an average of 4.3h of 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 value of 2, and less, symbolizes a low health risk from exposure to the Sun's UV rays for the average person.Note: A maximum high daily UV index of 2 during December translates into the following directions:
Babies, children, and those with sensitive skin should always avoid extended periods in the sun. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Employ a hat with a wide brim for robust protection, cutting UV exposure by half. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Saint John, WA
- Average high temperature in December: 33.1°F
The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is December (33.1°F).
- Average low temperature in December: 23.9°F
The month with the highest average low temperature is August (61.3°F).
The coldest month (with the lowest average low temperature) is December (23.9°F).
Average pressure in December
Saint John, WA
- Average pressure in December: 30.17"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is August (29.9"Hg).
Average wind speed in December
Saint John, WA
- Average wind speed in December: 7.1mph
The windiest month (with the highest average wind speed) is March (8.8mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity in December
Saint John, WA
- Average humidity in December: 85%
The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is August (36%).
Average rainfall in December
Saint John, WA
- Average rainfall in December: 0.79"
The wettest months (with the highest rainfall) are January and May (0.91").
The driest month (with the least rainfall) is July (0.16").
Average rainfall days in December
Saint John, WA
- Average rainfall days in December: 6.5 days
The month with the highest number of rainy days is March (10.1 days).
The month with the least rainy days is July (3.5 days).
Average snowfall in December
Saint John, WA
- Average snowfall in December: 2.91"
The month with the highest snowfall is February (3.82").
The months with the least snowfall are June, July, August and October (0").
Average snowfall days in December
Saint John, WA
- Average snowfall days in December: 9.3 days
The month with the highest number of snowfall days is December (9.3 days).
The months with the least snowfall days are June, July, August and October (0 days).
Average daylight in December /
Average sunshine in December
Saint John, 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: 4h and 18min
The month with the most sunshine is August (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 4h and 18min).
Average sunshine days in December
Saint John, WA
- Average sunshine days in December: 19.2 days
The month with the most sunshine days is July (26.6 days).
The month with the least sunshine days is February (15.9 days).
Average UV index in December
Saint John, 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
Saint John, WA
- Average cloud cover in December: 55
The months with the most cloud cover are January and December (Cloud cover 55).
The month with the least cloud cover is July (Cloud cover 11).
Average visibility in December
Saint John, WA
- Average visibility in December: 5mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (5mi).
