Weather & Climate in Grass Valley, OR

Temperature, precipitation, air quality, natural hazards, and monthly weather data.

Grass Valley experiences four distinct seasons with an average annual temperature of 49°F (9°C). Winters average 32°F in January while summers reach 69°F in July. The area gets 311 sunny days per year, well above the U.S. average of 205 / making it one of the sunnier locations in the country. Annual precipitation totals 11.0 inches (drier than the 38-inch national average). The area receives 16.6 inches of snow annually, a moderate snowfall amount. Air quality is rated Good with a median AQI of 32. The city sits at an elevation of 2,268 feet.

Temperature

32°F Jan (0°C) 69°F Jul (20°C)

Annual Average	49.0°F
	9% below US avg
January Average	32°F (0°C)
July Average	69°F (20°C)
Sunny Days	311 days/yr

Geography

Elevation	2,268 ft (691 m)
Area	0.5 sq mi (1.3 km²)
Population Density	316/sq mi
Coordinates	45.3591°N, 120.7842°W
Timezone	America/Los_Angeles
County	Sherman County County
Nearest Airport	Columbia Gorge Regional/The Dalles Municipal (DLS) 26 miles away

Precipitation & Snow

Annual Rainfall 11.0"

71% below US avg

Snowfall 16.6"

Wettest Month (Jan) 1.89"

Driest Month (Jul) 0.31"

Air Quality

AQI Median	32.0
Rating	Good

Natural Hazard Risk

Overall Risk	Very Low
Risk Score	2.9 / 100
Social Vulnerability	32.0 / 100
Community Resilience	42.8 / 100

Hazard Breakdown

Tornado	Very Low
Earthquake	Very Low
Wildfire	Relatively Moderate
Flood	Very Low
Hail	Very Low
Strong Wind	Very Low
Heat Wave	Very Low
Winter Weather	Very Low
Lightning	Very Low
Ice Storm	Relatively Low
Drought	Very Low
Cold Wave	Very Low
Landslide	Very Low
Volcano	Very Low
Avalanche	Very Low

Source: FEMA National Risk Index v1.20 (Dec 2025)

Earthquake History

954 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M5.6.

Mar 25, 1993	4 km E of Scotts Mills, Oregon	M5.6	147 km	20 km
Jun 29, 2002	6 km ENE of Government Camp, Oregon	M4.5	71 km	5 km
Jun 17, 2010	30 km S of White Swan, Washington	M4.2	83 km	3 km
Jul 14, 2008	11 km ESE of Maupin, Oregon	M4.2	29 km	16 km
Jan 30, 2000	6 km SE of Condon, Oregon	M4.1	55 km	-1 km
Oct 9, 1998	20 km S of White Swan, Washington	M4.0	94 km	2 km
Jun 6, 2021	6 km NE of Government Camp, Oregon	M3.9	71 km	4 km
Nov 18, 1997	20 km NW of Bickleton, Washington	M3.9	91 km	15 km
Oct 1, 2004	37 km NNE of Amboy, Washington	M3.9	144 km	-1 km
Mar 22, 1997	10 km ESE of Condon, Oregon	M3.9	59 km	0 km
Aug 7, 1992	8 km WSW of Irrigon, Oregon	M3.9	108 km	0 km
Jan 3, 2018	37 km SSE of Morton, Washington	M3.9	140 km	10 km
Jun 14, 2007	12 km ESE of Maupin, Oregon	M3.8	29 km	18 km
Jun 29, 2002	7 km NE of Government Camp, Oregon	M3.8	70 km	5 km
Oct 1, 2004	36 km NNE of Amboy, Washington	M3.7	144 km	-2 km
May 18, 2008	11 km SSW of Benton City, Washington	M3.7	131 km	20 km
Jun 8, 1993	5 km ESE of Scotts Mills, Oregon	M3.7	147 km	19 km
Jan 31, 2013	3 km ENE of Amboy, Washington	M3.7	141 km	6 km
Jul 25, 2006	37 km NNE of Amboy, Washington	M3.6	143 km	-1 km
Aug 5, 2006	37 km NNE of Amboy, Washington	M3.6	143 km	-1 km

Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.

Tornado History

6 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF0.

Date	Rating	Distance	Path	Fatalities
Apr 14, 2011	EF0	84 km	0.2 mi	0
Jun 9, 2004	EF0	86 km	0.5 mi	0
Jul 16, 1993	EF0	76 km	0.5 mi	0
May 11, 1970	EF0	73 km	0.1 mi	0
Oct 13, 1968	EF0	98 km	0.1 mi	0
Apr 12, 1957	EF0	57 km	16.2 mi	0

Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).

Tsunami History

1 tsunami recorded within 500 km. Highest wave on record: 250.0 m (820 ft).

Year	Location	Cause	Max Wave	Deaths	Distance
1980	WASHINGTON	Explosion	250.0 m	61	143 km

Source: NOAA/NCEI Historical Tsunami Database.

Nearby Volcanoes

12 volcanoes within 200 km. Closest: Hood (71 km).

Name	Type	Elevation	Last Eruption	Distance
Hood	Stratovolcano	3,426 m (11,240 ft)	1866	71 km
Indian Heaven	Shield(s)	1,806 m (5,925 ft)	-6250	103 km
Adams	Stratovolcano	3,742 m (12,277 ft)	950	109 km
Jefferson	Stratovolcano	3,199 m (10,495 ft)	950	110 km
West Crater	Volcanic field	1,329 m (4,360 ft)	-5750	116 km
Sand Mountain Field	Pyroclastic cone(s)	1,664 m (5,459 ft)	-950	141 km
St. Helens	Stratovolcano	2,549 m (8,363 ft)	2008	143 km
Belknap	Shield(s)	2,095 m (6,873 ft)	480	146 km
Three Sisters	Complex	3,159 m (10,364 ft)	440	157 km
Bachelor	Stratovolcano	2,763 m (9,065 ft)	-5800	169 km
Rainier	Stratovolcano	4,392 m (14,409 ft)	1450	182 km
Newberry	Shield	2,434 m (7,986 ft)	690	185 km

Source: Smithsonian Institution Global Volcanism Program (GVP).

Wildfire History

20 wildfires (100+ acres) recorded within 100 km. Largest: SIMNASHO (118,466 acres, 1996).

Year	Name	Acres Burned	Distance
1996	SIMNASHO	118,466	68 km
2018	BOXCAR 0410 RN	99,874	41 km
2000	MULE DRY	90,184	85 km
2011	HANCOCK COMPLEX	71,495	49 km
2017	NENA SPRINGS	70,074	54 km
2018	SUBSTATION 0730 RN	69,109	20 km
2015	COUNTY LINE 2	68,189	77 km
2011	0655 RAZOR BACK EAST	65,350	47 km
2023	NEWELL ROAD	61,833	65 km
2024	BIG HORN	51,023	78 km
2013	SUNNYSIDE TURNOFF	50,028	62 km
2018	STUBBLEFIELD 1008 RN	49,160	31 km
2017	EAGLE CREEK	48,816	95 km
2018	JENNIES PEAK 1039 RN	47,664	71 km
2008	COAL PLANT	45,801	91 km
2011	HIGH CASCADES	44,498	89 km
2014	BLACK ROCK	40,760	43 km
2014	SHANIKO BUTTE	39,852	49 km
2015	HIGHWAY 8	35,296	68 km
2018	LONG HOLLOW 0806 RN	33,662	15 km

Source: NIFC/IRWIN Wildfire Records (100+ acres).

Monthly Weather

Month	Avg Temperature	Precipitation	Summary
January	32°F (0°C)	1.9 in	Wettest
February	36°F (2°C)	1.3 in
March	42°F (5°C)	1.2 in
April	47°F (8°C)	1.0 in
May	54°F (12°C)	0.9 in
June	61°F (16°C)	0.7 in
July	69°F (20°C)	0.3 in	Warmest, Driest
August	67°F (20°C)	0.4 in
September	60°F (15°C)	0.6 in
October	50°F (10°C)	0.9 in
November	39°F (4°C)	1.9 in
December	32°F (0°C)	1.9 in	Coldest

Grass Valley has a seasonal temperature swing of 36°F / from 32°F in December to 69°F in July. Total annual precipitation is 12.9 inches, with January being the wettest month (1.9") and July the driest (0.3").

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