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 46.2°F (7.9°C), showing minimal deviation from the previous month. An average low-temperature of 35.2°F (1.8°C) is expected during January.Humidity
January, February and December, with an average relative humidity of 83%, are the most humid months.Rainfall
In Portland, in January, it is raining for 18.3 days, with typically 4.33" (110mm) of accumulated precipitation. In Portland, during the entire year, the rain falls for 173.1 days and collects up to 31.18" (792mm) of precipitation.Snowfall
January through March, November and December are months with snowfall. In Portland, in January, during 1.3 snowfall days, 0.91" (23mm) of snow is typically accumulated. Throughout the year, in Portland, there are 6.4 snowfall days, and 3.94" (100mm) of snow is accumulated.Daylight
The average length of the day in January is 9h and 11min.On the first day of the month, sunrise is at 7:50 am and sunset at 4:37 pm. On the last day of January, sunrise is at 7:32 am and sunset at 5:15 pm PST.
Sunshine
January has the least sunshine of the year, with an average of 4.1h 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 reading of 2, and below, represents a low health risk from unsafe exposure to UV radiation for the ordinary person.Note: The maximum daily UV index, 2 in January, converts into the following recommendations:
Most individuals face no major issues with lengthy exposure to the sun, but children, infants, and individuals with fair skin always require protection. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are January temperatures?
What are the most humid months?
What is the average humidity in January?
How many days does it rain in January?
How much does it snow in January?
What is the average length of the day in January?
What time are sunrise and sunset in January?
What is the month with the least sunshine in Portland?
How long on average sun shines in January?
When is the lowest UV index?
What is the UV index reading in January?
Average temperature in January
Portland, OR
- Average high temperature in January: 46.2°F
The warmest month (with the highest average high temperature) is August (81.5°F).
The month with the lowest average high temperature is December (44.1°F).
- Average low temperature in January: 35.2°F
The month with the highest average low temperature is August (55°F).
The coldest month (with the lowest average low temperature) is December (34.7°F).
Average pressure in January
Portland, OR
- Average pressure in January: 30.12"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed in January
Portland, OR
- Average wind speed in January: 5.8mph
The windiest month (with the highest average wind speed) is January (5.8mph).
The calmest month (with the lowest average wind speed) is August (3.9mph).
Average humidity in January
Portland, OR
- Average humidity in January: 83%
The months with the highest relative humidity are January, February and December (83%).
The month with the lowest relative humidity is August (63%).
Average rainfall in January
Portland, OR
- Average rainfall in January: 4.33"
The wettest month (with the highest rainfall) is December (4.53").
The driest month (with the least rainfall) is July (0.31").
Average rainfall days in January
Portland, OR
- Average rainfall days in January: 18.3 days
The month with the highest number of rainy days is March (20.4 days).
The month with the least rainy days is July (4.9 days).
Average snowfall in January
Portland, OR
- Average snowfall in January: 0.91"
The month with the highest snowfall is March (1.5").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in January
Portland, OR
- Average snowfall days in January: 1.3 days
The month with the highest number of snowfall days is February (2.3 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
Portland, OR
- Average daylight in January: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in January: 4h and 1min
The month with the most sunshine is August (Average sunshine: 10h and 54min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in January
Portland, OR
- Average sunshine days in January: 10.8 days
The months with the most sunshine days are July and August (23.8 days).
The month with the least sunshine days is March (8.3 days).
Average UV index in January
Portland, OR
- 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
Portland, OR
- Average cloud cover in January: 57
The month with the most cloud cover is February (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 23).
Average visibility in January
Portland, OR
- Average visibility in January: 5mi
The months with the highest visibility are July, August and September (6mi).
The months with the lowest visibility are January, February, March, April, May, June, October, November and December (5mi).
Portland, Oregon, USA
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