Contents
- Weather in January
- Frequently asked questions
- Average temperature in January
- Average pressure in January
- Average wind speed in January
- Average humidity in January
- Average rainfall in January
- Average rainfall days in January
- Average snowfall in January
- Average snowfall days in January
- Average daylight in January
- Average sunshine in January
- Average sunshine days in January
- Average UV index in January
- Average cloud cover in January
- Average visibility in January
Weather in January
Temperature
The beginning of January reveals an average high-temperature of a still frosty 44.4°F (6.9°C), showing minimal deviation from the previous month. Mercer Island records a mean low-temperature of 35.2°F (1.8°C) in January.Humidity
The most humid month is January, with an average relative humidity of 85%.Rainfall
In Mercer Island, in January, during 11.8 rainfall days, 1.54" (39mm) of precipitation is typically accumulated. Throughout the year, there are 119.1 rainfall days, and 11.97" (304mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through March, November and December. In January, in Mercer Island, it is snowing for 1.3 days. Throughout January, 0.67" (17mm) of snow is accumulated. In Mercer Island, during the entire year, snow falls for 7 days and aggregates up to 3.27" (83mm) of snow.Daylight
The average length of the day in January is 8h and 58min.On the first day of the month, sunrise is at 7:56 am and sunset at 4:27 pm. On the last day of January, in Mercer Island, sunrise is at 7:36 am and sunset at 5:07 pm PST.
Sunshine
In Mercer Island, the average sunshine in January is 4.4h.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 reading of 2, and below, represents a low health risk from exposure to the Sun's UV rays for average individuals.Note: In January, a daily UV index of 2 turns into the following recommendations:
Many can withstand an hour in the sun without burning, yet children must always have protection against sunlight. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly. Remember to consider! The UV radiation from the Sun can be intensified nearly twice by the reflection of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is January in Mercer Island?
What is the most humid month in Mercer Island?
What is the average humidity in January in Mercer Island?
How much does it rain in Mercer Island in January?
How many days does it snow in January in Mercer Island?
How many hours of daylight does Mercer Island have in January?
When is the sunrise / sunset in January in Mercer Island?
How long on average sun shines in January in Mercer Island?
What is the month with the lowest UV index in Mercer Island?
How high is the UV index in January in Mercer Island?
Average temperature in January
Mercer Island, WA
- Average high temperature in January: 44.4°F
The warmest month (with the highest average high temperature) is August (76.6°F).
The month with the lowest average high temperature is December (42.8°F).
- Average low temperature in January: 35.2°F
The month with the highest average low temperature is August (53.4°F).
The coldest month (with the lowest average low temperature) is February (34.5°F).
Average pressure in January
Mercer Island, WA
- Average pressure in January: 30.1"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 January
Mercer Island, WA
- Average wind speed in January: 5mph
The windiest month (with the highest average wind speed) is March (5.1mph).
The calmest month (with the lowest average wind speed) is August (3.4mph).
Average humidity in January
Mercer Island, WA
- Average humidity in January: 85%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is July (69%).
Average rainfall in January
Mercer Island, WA
- Average rainfall in January: 1.54"
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 January
Mercer Island, WA
- Average rainfall days in January: 11.8 days
The month with the highest number of rainy days is March (13.7 days).
The month with the least rainy days is August (4.1 days).
Average snowfall in January
Mercer Island, WA
- Average snowfall in January: 0.67"
The month with the highest snowfall is February (1.77").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in January
Mercer Island, WA
- Average snowfall days in January: 1.3 days
The month with the highest number of snowfall days is February (3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in January /
Average sunshine in January
Mercer Island, WA
- Average daylight in January: 9h and 0min
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 January: 4h and 2min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 12min).
Average sunshine days in January
Mercer Island, WA
- Average sunshine days in January: 17.1 days
The month with the most sunshine days is August (24.9 days).
The month with the least sunshine days is February (13.8 days).
Average UV index in January
Mercer Island, WA
- Average UV index in January: 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 January
Mercer Island, WA
- Average cloud cover in January: 55
The month with the most cloud cover is December (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 25).
Average visibility in January
Mercer Island, WA
- Average visibility in January: 5mi
The months with the highest visibility are May, June, July, August and September (6mi).
The months with the lowest visibility are January, February, March, April, October, November and December (5mi).
Mercer Island, Washington, USA
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