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 month in Issaquah, Washington, is December, with an average high-temperature of 42.3°F (5.7°C) and an average low-temperature of 33.4°F (0.8°C).Humidity
The average relative humidity in December is 84%.Rainfall
December is the month with the most rainfall in Issaquah, Washington. Rain falls for 13.7 days and accumulates 2.01" (51mm) of precipitation.Snowfall
Months with snowfall in Issaquah are January through April, November and December. In Issaquah, in December, snow falls for 0.8 days, with typically accumulated 0.16" (4mm) of snow. In Issaquah, during the entire year, snow falls for 5.9 days and aggregates up to 1.93" (49mm) of snow.Daylight
With an average of 8h and 30min of daylight, December has the shortest days of the year in Issaquah.On the first day of December in Issaquah, sunrise is at 7:36 am and sunset at 4:18 pm. On the last day of the month, sunrise is at 7:55 am and sunset at 4:27 pm PST.
Sunshine
December has the least sunshine of the year, with an average of 4h 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 estimate of 2, and below, represents a low health risk from unprotected exposure to Sun's UV rays for average individuals.Note: The UV index of 2 during December leads to these advisories:
Although the majority can endure up to an hour in the sun without burns, children always require sun protection. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.
Frequently asked questions
What part of the year is the coldest in Issaquah?
Is December cold in Issaquah?
What is the average humidity in December in Issaquah?
What is the rainiest month in Issaquah?
How many days does it rain in December in Issaquah?
How many days does it snow in December in Issaquah?
What is the month with the shortest days in Issaquah?
How many hours of daylight does Issaquah have in December?
What time are sunrise and sunset in December in Issaquah?
What is the month with the least sunshine in Issaquah?
How many hours of sunshine does Issaquah have in December?
What is the month with the lowest UV index in Issaquah?
How high is the UV index in December in Issaquah?
Average temperature in December
Issaquah, WA
- Average high temperature in December: 42.3°F
The warmest month (with the highest average high temperature) is August (77°F).
The month with the lowest average high temperature is December (42.3°F).
- Average low temperature in December: 33.4°F
The month with the highest average low temperature is August (51.4°F).
The coldest months (with the lowest average low temperature) are February and December (33.4°F).
Average pressure in December
Issaquah, WA
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed in December
Issaquah, WA
- Average wind speed in December: 4.7mph
The windiest month (with the highest average wind speed) is January (5.1mph).
The calmest month (with the lowest average wind speed) is August (3.4mph).
Average humidity in December
Issaquah, WA
- Average humidity in December: 84%
The months with the highest relative humidity are January and February (85%).
The month with the lowest relative humidity is July (69%).
Average rainfall in December
Issaquah, WA
- Average rainfall in December: 2.01"
The wettest month (with the highest rainfall) is December (2.01").
The driest month (with the least rainfall) is July (0.24").
Average rainfall days in December
Issaquah, WA
- Average rainfall days in December: 13.7 days
The month with the highest number of rainy days is March (14.8 days).
The month with the least rainy days is August (4.3 days).
Average snowfall in December
Issaquah, WA
- Average snowfall in December: 0.16"
The month with the highest snowfall is February (0.94").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Issaquah, WA
- Average snowfall days in December: 0.8 days
The month with the highest number of snowfall days is February (2.5 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
Issaquah, WA
- Average daylight in December: 8h and 3min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in December: 4h and 0min
The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is December (Average sunshine: 4h and 0min).
Average sunshine days in December
Issaquah, WA
- Average sunshine days in December: 14.8 days
The month with the most sunshine days is August (25 days).
The month with the least sunshine days is February (12.9 days).
Average UV index in December
Issaquah, WA
- Average UV index in December: 2
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Issaquah, WA
- Average cloud cover in December: 58
The months with the most cloud cover are January and December (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in December
Issaquah, WA
- Average visibility in December: 4mi
The months with the highest visibility are July and August (6mi).
The months with the lowest visibility are January, February and December (4mi).
Issaquah, Washington, USA
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