January weather - Winter 2025

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

The red tree colors of the fall along a road and amid trees in this tranquil neighborhood in Hillsboro, Oregon

Weather in January

January temperatures in Hillsboro, Oregon set the tone for the year with cold highs averaging around 45.3°F (7.4°C) and the lowest typically registering at 34.7°F (1.5°C). The city has a predominantly cloud-filled sky, with humidity at its peak, leading to frequent rainfall. The chilly month witnesses occasional snowfall, transforming the city into a picturesque, winter wonderland. The limited sunshine, averaging around 3.8 hours per day, does little to take away the winter chill. In stark contrast to the dry summer months, the land is moist and contributes to vibrant, green scenery.

Temperature

The shift to January signals an average high-temperature of a still frosty 45.3°F (7.4°C), subtly varied from December's 43.9°F (6.6°C). Throughout January, an average nighttime temperature of 34.7°F (1.5°C) is experienced.

Humidity

The months with the highest humidity are January, February, November and December, with an average relative humidity of 85%.

Rainfall

January is the month with the most rainfall in Hillsboro. Rain falls for 18.8 days and accumulates 4.57" (116mm) of precipitation.

Snowfall

Months with snowfall are January through March, November and December. In January, it is snowing for 1.6 days. Throughout January, 0.79" (20mm) of snow is accumulated. Throughout the year, there are 6.6 snowfall days, and 4.53" (115mm) of snow is accumulated.

Daylight

In Hillsboro, the average length of the day in January is 9h and 11min.
On the first day of January, sunrise is at 7:52 am and sunset at 4:38 pm. On the last day of the month, sunrise is at 7:34 am and sunset at 5:16 pm PST.

Sunshine

In Hillsboro, the average sunshine in January is 3.8h.

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 value of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for the average person.
Note: In January, the average maximum UV index of 2 translates into the following recommendations:
Babies, children, and those with sensitive skin should always avoid extended periods in the sun. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Boost your sun resistance with garments that are densely woven yet spacious. Be vigilant! The reflective nature of snow can increase the Sun's UV radiation nearly twofold.

Updated: Jun 4, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in January?

In January, in Hillsboro, the average high-temperature is 45.3°F (7.4°C), and the average low-temperature is 34.7°F (1.5°C).

What are the most humid months?

January, February, November and December, with an average relative humidity of 85%, are most humid months.

What is the average humidity in January?

In Hillsboro, the average relative humidity in January is 85%.

What is the rainiest month?

January is the month with the most rainfall. Rain falls for 18.8 days and accumulates 4.57" (116mm) of precipitation.

How much does it rain in January?

In January, the rain falls for 18.8 days. Throughout January, 4.57" (116mm) of precipitation is accumulated.

How many days does it snow in January?

In Hillsboro, in January, during 1.6 snowfall days, 0.79" (20mm) of snow is typically accumulated.

How many hours of daylight does Hillsboro have in January?

In Hillsboro, the average day length in January is 9h and 11min.

What time are sunrise and sunset in January?

In January, on the first day of the month, sunrise is at 7:52 am and sunset at 4:38 pm. On the last day of the month, sunrise is at 7:34 am and sunset at 5:16 pm PST.

How many hours of sunshine does Hillsboro have in January?

The average sunshine duration in January is 3.8h.

What is the month with the lowest UV index?

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index.

What is the UV index reading in January?

In Hillsboro, the average daily maximum UV index in January is 2. A UV Index estimate of 2, and below, represents a low health risk from exposure to Sun's UV rays.

Today

Tomorrow

Long-term

Year January F M A M J J A S O N D

Dec

January

Feb

Average high temperature

43.9°F 6.6°C

45.3°F 7.4°C

47.3°F 8.5°C

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

5.2mph 8.4km/h

5.5mph 8.9km/h

5.4mph 8.7km/h

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average snowfall

Average snowfall days

Average daylight

Average sunshine

Average sunshine days

10.5

10.8

8.9

Average UV index

Average cloud cover

Average visibility

Average temperature in January
Hillsboro, OR

Average high temperature in January: 45.3°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 (43.9°F).

Average low temperature in January: 34.7°F

The month with the highest average low temperature is August (55.4°F).
The coldest month (with the lowest average low temperature) is December (34°F).

Average pressure in January
Hillsboro, OR

Average pressure in January: 30.11"Hg

The month with the highest atmospheric pressure is January (30.11"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).

Average wind speed in January
Hillsboro, OR

Average wind speed in January: 4.9mph

The windiest month (with the highest average wind speed) is March (5mph).
The calmest months (with the lowest average wind speed) are June, August and September (4.3mph).

Average humidity in January
Hillsboro, OR

Average humidity in January: 85%

The months with the highest relative humidity are January, February, November and December (85%).
The month with the lowest relative humidity is August (64%).

Average rainfall in January
Hillsboro, OR

Average rainfall in January: 4.57"

The wettest month (with the highest rainfall) is January (4.57").
The driest month (with the least rainfall) is August (0.31").

Average rainfall days in January
Hillsboro, OR

Average rainfall days in January: 18.8 days

The month with the highest number of rainy days is March (20.8 days).
The month with the least rainy days is August (4.4 days).

Average snowfall in January
Hillsboro, OR

Average snowfall in January: 0.79"

The month with the highest snowfall is February (1.81").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in January
Hillsboro, OR

Average snowfall days in January: 1.6 days

The month with the highest number of snowfall days is February (2.4 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).

Average daylight in January /
Average sunshine in January
Hillsboro, 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: 3h and 5min

The month with the most sunshine is August (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 3h and 42min).

Average sunshine days in January
Hillsboro, OR

Average sunshine days in January: 10.8 days

The month with the most sunshine days is July (24.4 days).
The month with the least sunshine days is March (8.5 days).

Average UV index in January
Hillsboro, 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
Hillsboro, OR

Average cloud cover in January: 61

The month with the most cloud cover is February (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 25).

Average visibility in January
Hillsboro, OR

Average visibility in January: 4mi

The months with the highest visibility are July, August and September (6mi).
The months with the lowest visibility are January and February (4mi).

January weather forecast
Hillsboro, OR

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