January weather forecast
Grass Valley, OR

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Weather in January

January, like December, in Grass Valley, Oregon, is another cold winter month, with an average temperature fluctuating between 38.5°F (3.6°C) and 28°F (-2.2°C).

Temperature

The weather during January records an average high-temperature of a still cold 38.5°F (3.6°C), closely mirroring the preceding month. Grass Valley's average low-temperature in January is measured at a subzero cold 28°F (-2.2°C).

Humidity

With an average relative humidity of 84%, January is the most humid month in Grass Valley, Oregon.

Rainfall

January is the month with the most rainfall. Rain falls for 13.3 days and accumulates 1.93" (49mm) of precipitation.

Snowfall

January through March, November and December are months with snowfall. In January, it is snowing for 3.1 days. Throughout January, 1.97" (50mm) of snow is accumulated. Throughout the year, there are 12.6 snowfall days, and 7.6" (193mm) of snow is accumulated.

Daylight

In January, the average length of the day is 9h and 13min.
On the first day of January, sunrise is at 7:42 am and sunset at 4:30 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 5:08 pm PST.

Sunshine

With an average of 5h of sunshine, January has the least sunshine of the year.

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 value of 2, and less, symbolizes a low threat to health from unsafe exposure to UV radiation for the ordinary person.
Note: In January, a daily maximum UV index of 2 leads to the following instructions:
Prolonged sun exposure should always be prevented in babies, children, and those with sensitive skin. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Consider carefully! The reflective quality of snow can almost double the intensity of the Sun's UV radiation.
Updated: Jul 19, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is January?

The high-temperature during January is 38.5°F (3.6°C) and the low-temperature is 28°F (-2.2°C).

What is the most humid month?

With an average relative humidity of 84%, January is the most humid month.

What is the average humidity in January?

In Grass Valley, the average relative humidity in January is 84%.

What is the rainiest month?

January is the month with the most rainfall. Rain falls for 13.3 days and accumulates 1.93" (49mm) of precipitation.

How much does it rain in January?

In Grass Valley, in January, during 13.3 rainfall days, 1.93" (49mm) of precipitation is typically accumulated.

How much does it snow in January?

In Grass Valley, in January, during 3.1 snowfall days, 1.97" (50mm) of snow is typically accumulated.

How many hours of daylight does Grass Valley have in January?

In January, the average day length is 9h and 13min.

When is the sunrise / sunset in January?

On the first day of January in Grass Valley, sunrise is at 7:42 am and sunset at 4:30 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 5:08 pm PST.

What is the month with the least sunshine in Grass Valley?

January has the least sunshine of the year in Grass Valley, with an average of 5h of sunshine.

How many hours of sunshine does Grass Valley have in January?

In January, the average sunshine duration is 5h.

When is the lowest UV index?

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

What is the UV index intensity in January?

In Grass Valley, the average daily maximum UV index in January is 2. A UV Index value of 2, and less, symbolizes a low health risk from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in January
Grass Valley, OR

Average temperature in January - Grass Valley, OR
  • Average high temperature in January: 38.5°F

The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is December (37.4°F).

  • Average low temperature in January: 28°F

The month with the highest average low temperature is August (57.9°F).
The coldest month (with the lowest average low temperature) is December (27°F).

Average pressure in January
Grass Valley, OR

Average pressure in January - Grass Valley, OR
  • Average pressure in January: 30.16"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is August (29.95"Hg).

Average wind speed in January
Grass Valley, OR

Average wind speed in January - Grass Valley, OR
  • Average wind speed in January: 5mph

The windiest month (with the highest average wind speed) is June (7.9mph).
The calmest months (with the lowest average wind speed) are January and December (5mph).

Average humidity in January
Grass Valley, OR

Average humidity in January - Grass Valley, OR
  • Average humidity in January: 84%

The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is August (46%).

Average rainfall in January
Grass Valley, OR

Average rainfall in January - Grass Valley, OR
  • Average rainfall in January: 1.93"

The wettest month (with the highest rainfall) is January (1.93").
The driest month (with the least rainfall) is July (0.12").

Average rainfall days in January
Grass Valley, OR

Average rainfall days in January - Grass Valley, OR
  • Average rainfall days in January: 13.3 days

The month with the highest number of rainy days is March (14.3 days).
The month with the least rainy days is July (2.9 days).

Average snowfall in January
Grass Valley, OR

Average snowfall in January - Grass Valley, OR
  • Average snowfall in January: 1.97"

The month with the highest snowfall is February (2.87").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in January
Grass Valley, OR

Average snowfall days in January - Grass Valley, OR
  • Average snowfall days in January: 3.1 days

The months with the highest number of snowfall days are February and December (3.9 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
Grass Valley, OR

Average daylight in January / Average sunshine in January - Grass Valley, 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: 5h

The months with the most sunshine are July and August (Average sunshine: 12h).
The month with the least sunshine is January (Average sunshine: 5h).

Average sunshine days in January
Grass Valley, OR

Average sunshine days in January - Grass Valley, OR
  • Average sunshine days in January: 13.6 days

The month with the most sunshine days is July (27 days).
The month with the least sunshine days is February (12.3 days).

Average UV index in January
Grass Valley, OR

Average UV index in January - Grass Valley, 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
Grass Valley, OR

Average cloud cover in January - Grass Valley, OR
  • Average cloud cover in January: 49

The month with the most cloud cover is January (Cloud cover 49).
The months with the least cloud cover are July and August (Cloud cover 9).

Average visibility in January
Grass Valley, OR

Average visibility in January - Grass Valley, OR
  • Average visibility in January: 5mi

The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (5mi).

Grass Valley, Oregon, USA

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