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 weather during January records an average high-temperature of a still wintry 35.4°F (1.9°C), closely mirroring the preceding month. In Mattawa, the nighttime temperature averages to a subzero cold 25.9°F (-3.4°C) during January.Humidity
The most humid month is January, with an average relative humidity of 83%.Rainfall
The months with the most rainfall are January and December, with an average 0.87" (22mm) of precipitation.Snowfall
January through April, September, November and December are months with snowfall. In Mattawa, in January, snow falls for 6.3 days, with typically accumulated 2.99" (76mm) of snow. Throughout the year, there are 22.3 snowfall days, and 10" (254mm) of snow is accumulated.Daylight
The average length of the day in January is 9h and 4min.On the first day of the month, sunrise is at 7:44 am and sunset at 4:21 pm. On the last day of January, sunrise is at 7:25 am and sunset at 5:00 pm PST.
Sunshine
January has the least sunshine of the year, with an average of 4.9h 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 of 2, and less, symbolizes a low health risk from unprotected exposure to Sun's UV rays for the average person.Note: The average daily UV index of 2 in January transforms into the following instructions:
While most people are not greatly affected by extended sun exposure, those with fair skin, babies, and children must always have protection. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Tightly woven clothing, when worn loosely, shields effectively against the Sun. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in January?
What is the most humid month?
What is the average humidity in January?
What is the wettest month?
How many days does it rain in January?
How much does it snow in January?
How many hours of daylight does Mattawa have in January?
When is the sunrise / sunset in January?
What is the month with the least sunshine?
How long on average sun shines in January?
What are the months with the lowest UV index?
What is the UV index intensity in January?
Average temperature in January
Mattawa, WA
- Average high temperature in January: 35.4°F
The warmest months (with the highest average high temperature) are July and August (88.3°F).
The month with the lowest average high temperature is December (34.5°F).
- Average low temperature in January: 25.9°F
The month with the highest average low temperature is August (61.5°F).
The coldest month (with the lowest average low temperature) is December (24.3°F).
Average pressure in January
Mattawa, WA
- Average pressure in January: 30.17"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in January
Mattawa, WA
- Average wind speed in January: 4.9mph
The windiest month (with the highest average wind speed) is April (7.6mph).
The calmest month (with the lowest average wind speed) is December (4.7mph).
Average humidity in January
Mattawa, WA
- Average humidity in January: 83%
The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is July (37%).
Average rainfall in January
Mattawa, WA
- Average rainfall in January: 0.87"
The wettest months (with the highest rainfall) are January and December (0.87").
The driest month (with the least rainfall) is August (0.2").
Average rainfall days in January
Mattawa, WA
- Average rainfall days in January: 8.5 days
The month with the highest number of rainy days is March (10.6 days).
The month with the least rainy days is August (3.5 days).
Average snowfall in January
Mattawa, WA
- Average snowfall in January: 2.99"
The month with the highest snowfall is December (3.43").
The months with the least snowfall are May, June, July, August and October (0").
Average snowfall days in January
Mattawa, WA
- Average snowfall days in January: 6.3 days
The month with the highest number of snowfall days is December (6.5 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in January /
Average sunshine in January
Mattawa, WA
- Average daylight in January: 9h and 1min
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 January: 4h and 5min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 54min).
Average sunshine days in January
Mattawa, WA
- Average sunshine days in January: 18 days
The months with the most sunshine days are July and August (25.8 days).
The month with the least sunshine days is February (16 days).
Average UV index in January
Mattawa, WA
- Average UV index in January: 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 January
Mattawa, WA
- Average cloud cover in January: 47
The month with the most cloud cover is January (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 10).
Average visibility in January
Mattawa, WA
- Average visibility in January: 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).
Mattawa, Washington, USA
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