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
December
Weather in December
Temperature
Issaquah's coldest weather arrives in December, when temperatures average a high of 42.3°F (5.7°C) and a low of 33.4°F (0.8°C).Humidity
In Issaquah, the average relative humidity in December is 84%.Rainfall
December is the month with the most rainfall. Rain falls for 13.7 days and accumulates 2.01" (51mm) of precipitation.Snowfall
January through April, November and December are months with snowfall. In Issaquah, Washington, during December, snow falls for 0.8 days and regularly aggregates up to 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
The month with the shortest days is December, with an average of 8h and 30min of daylight.On the first day of the month, sunrise is at 7:36 am and sunset at 4:18 pm. On the last day of December, sunrise is at 7:55 am and sunset at 4:27 pm PST.
Sunshine
With an average of 4h of sunshine, December has the least sunshine of the year.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 threat to health from exposure to the Sun's UV radiation for ordinary individuals.Note: The maximum daily UV index of 2 during December translates into the following directions:
Prolonged exposure to sunlight rarely troubles the majority, but constant protection is vital for babies, children, and fair-skinned people. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Be cautious! The UV radiation from the Sun can be magnified almost twofold by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the coldest months?
Is it cold during December?
What is the average humidity in December?
What is the wettest month in Issaquah?
How many days does it rain in December?
How many days does it snow in December?
What is the month with the shortest days in Issaquah?
How many hours of daylight does Issaquah have in December?
When is the sunrise / sunset in December?
What is the month with the least sunshine?
How long on average sun shines in December?
What are the months with the lowest UV index in Issaquah?
How high is the UV index in December?
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).