Climate and monthly weather forecast
Grass Valley, OR

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Weather in January

January, the same as December, is an icy winter month in Grass Valley, Oregon, with an average temperature fluctuating between 38.5°F (3.6°C) and 28°F (-2.2°C). January commences with an average high-temperature of a still cold 38.5°F (3.6°C), showing little deviation from December's 37.4°F (3°C). Weather in January »

Weather in February

February, the last month of the winter in Grass Valley, is also a wintry month, with an average temperature fluctuating between 41.7°F (5.4°C) and 29.7°F (-1.3°C). Shifting into February, Grass Valley records an average high-temperature of a still icy 41.7°F (5.4°C), presenting minor fluctuations compared to the previous month. Weather in February »

Weather in March

The first month of the spring, March, is a frosty month in Grass Valley, Oregon, with temperature in the range of an average low of 33.4°F (0.8°C) and an average high of 49.1°F (9.5°C). Grass Valley observes a slight uplift in the average high-temperature with the onset of March, adjusting from February's cold 41.7°F (5.4°C) to a chilly 49.1°F (9.5°C). Weather in March »

Weather in April

April in Grass Valley, Oregon, is a mild spring month, with an average temperature fluctuating between 38.5°F (3.6°C) and 57.4°F (14.1°C). A minor escalation in the average high-temperature is seen with the onset of April, moving from a frosty 49.1°F (9.5°C) in March to a mild 57.4°F (14.1°C). Weather in April »

Weather in May

May, the last month of the spring in Grass Valley, is a comfortable month, with an average temperature ranging between max 67.3°F (19.6°C) and min 45°F (7.2°C). Observing a rise in May, the average high-temperature goes from April's moderate 57.4°F (14.1°C) to a still refreshing 67.3°F (19.6°C). Weather in May »

Weather in June

June, the first month of the summer in Grass Valley, is a warm month, with temperature in the range of an average low of 50.2°F (10.1°C) and an average high of 73.9°F (23.3°C). The beginning of June marks a minor shift in the average high-temperature, moving from May's comfortable 67.3°F (19.6°C) to a moderately hot 73.9°F (23.3°C). Weather in June »

Weather in July

July, the same as June, is another warm summer month in Grass Valley, Oregon, with temperature in the range of an average low of 56.8°F (13.8°C) and an average high of 83.5°F (28.6°C). July is the warmest month, with the temperature often reaching an average high of 83.5°F (28.6°C) and an average low of 56.8°F (13.8°C). The average heat index in July is computed to be 84.2°F (29°C). Weather in July »

Weather in August

August, the last month of the summer in Grass Valley, is also a moderately hot month, with an average temperature varying between 83.3°F (28.5°C) and 57.9°F (14.4°C). August notes an average high-temperature of a still moderately hot 83.3°F (28.5°C), subtly differing from July's 83.5°F (28.6°C). Weather in August »

Weather in September

The first month of the autumn, September, is also an agreeable month in Grass Valley, Oregon, with an average temperature varying between 52.7°F (11.5°C) and 73.2°F (22.9°C). The onset of September entails a temperature shift, as the average high-temperature decreases from a warm 83.3°F (28.5°C) in August to an agreeable 73.2°F (22.9°C). Weather in September »

Weather in October

October, like September, is another refreshing autumn month in Grass Valley, Oregon, with temperature in the range of an average high of 58.8°F (14.9°C) and an average low of 43.7°F (6.5°C). October comes with a decrease in the average high-temperature, falling from a pleasant 73.2°F (22.9°C) in September to a mild 58.8°F (14.9°C). Weather in October »

Weather in November

The last month of the autumn, November, is another chilly month in Grass Valley, Oregon, with an average temperature ranging between min 34.5°F (1.4°C) and max 46°F (7.8°C). The arrival of November corresponds with a temperature reduction, down from October's moderate 58.8°F (14.9°C) to a chilly 46°F (7.8°C). Weather in November »

Weather in December

The first month of the winter, December, is also a wintry month in Grass Valley, Oregon, with an average temperature fluctuating between 37.4°F (3°C) and 27°F (-2.8°C). With average high temperatures of 37.4°F (3°C) and lows of 27°F (-2.8°C), December is the coldest month. Weather in December »

Frequently asked questions

What is the most humid month?

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

What is the rainiest month?

The month with the most rainfall is January, when the rain falls for 13.3 days and typically aggregates up to 1.93" (49mm) of precipitation.

How many days does it rain?

Throughout the year, there are 112.2 rainfall days, and 10.91" (277mm) of precipitation is accumulated.

When does it snow?

Months with snowfall are January through March, November and December.

How many days does it snow in Grass Valley?

Throughout the year, there are 12.6 snowfall days, and 7.6" (193mm) of snow is accumulated.

What is the month with the least sunshine?

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

What is the month with 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 snowiest month?

The month with the most snowfall is February, when snow falls for 3.9 days and typically aggregates up to 2.87" (73mm) of snow.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from PST to PDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from PDT to PST.

When it does not snow?

In Grass Valley, snow does not fall in April through October.

When are the longest days?

With an average of 15h and 36min of daylight, June has the longest days of the year.

What time of the year is the hottest?

July is the warmest month, with the temperature often reaching an average high of 83.5°F (28.6°C) and an average low of 56.8°F (13.8°C).

What is the driest month?

The month with the least rainfall is July, when the rain falls for 2.9 days and typically collects 0.12" (3mm) of precipitation.

What are the months with the most sunshine?

The months with the most sunshine are July and August, with an average of 12h of sunshine.

What is the month with the highest UV index?

The month with the highest UV index is July, with an average maximum UV index of 6.

What is the least humid month in Grass Valley?

The least humid month is August, with an average relative humidity of 46%.

What time of the year is the coldest?

Grass Valley's December weather, with an average high temperature of 37.4°F (3°C) and an average low temperature of 27°F (-2.8°C), tends to be the coldest of the year.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 8h and 48min of daylight.

Average temperature
Grass Valley, OR

Average temperature - Grass Valley, OR

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).

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
Grass Valley, OR

Average pressure - Grass Valley, OR

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
Grass Valley, OR

Average wind speed - Grass Valley, OR

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
Grass Valley, OR

Average humidity - Grass Valley, OR

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

Average rainfall
Grass Valley, OR

Average rainfall - Grass Valley, OR

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
Grass Valley, OR

Average rainfall days - Grass Valley, OR

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
Grass Valley, OR

Average snowfall - Grass Valley, OR

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
Grass Valley, OR

Average snowfall days - Grass Valley, OR

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 / Average sunshine
Grass Valley, OR

Average daylight / Average sunshine - Grass Valley, OR

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).

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
Grass Valley, OR

Average sunshine days - Grass Valley, OR

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
Grass Valley, OR

Average UV index - Grass Valley, OR

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 visibility
Grass Valley, OR

Average visibility - Grass Valley, OR

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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