Weather & Climate in Sumpter, OR
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Sumpter experiences four distinct seasons with an average annual temperature of 48°F (9°C). Winters average 29°F in January while summers reach 69°F in July. Annual precipitation totals 19.3 inches (drier than the 38-inch national average). The area receives 78.6 inches of snow annually, making winter weather a significant factor for residents. Air quality is rated Good with a median AQI of 28 / among the cleanest air in the country. 76% of days have good air quality. The city sits at an elevation of 4,463 feet.
Temperature
29°F Jan (-2°C)
69°F Jul (20°C)
| Annual Average | 47.6°F |
| 12% below US avg | |
| January Average | 29°F (-2°C) |
| July Average | 69°F (20°C) |
Geography
| Elevation | 4,463 ft (1,360 m) |
| Area | 2.2 sq mi (5.6 km²) |
| Population Density | 87/sq mi |
| Coordinates | 44.7435°N, 118.1975°W |
| Timezone | America/Los_Angeles |
| County | Baker County County |
| Nearest Airport | Grant County Regional/Ogilvie Field (JDA) 45 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 28.0 |
| Rating | Good |
| Good Days % | 76.2% |
| Unhealthy Days | 3 |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 48.2 / 100 |
| Social Vulnerability | 69.4 / 100 |
| Community Resilience | 46.0 / 100 |
Hazard Breakdown
| Tornado | Very Low |
| Earthquake | Relatively Low |
| Wildfire | Relatively Moderate |
| Flood | Relatively Low |
| Hail | Relatively Low |
| Strong Wind | Very Low |
| Heat Wave | Relatively Low |
| Winter Weather | Relatively Moderate |
| Lightning | Very Low |
| Ice Storm | Very Low |
| Drought | Very Low |
| Cold Wave | Very Low |
| Landslide | Relatively Low |
| Volcano | Very Low |
| Avalanche | Relatively High |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
79 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.3.
| Nov 28, 1991 | 7 km S of Walla Walla East, Washington | M4.3 | 139 km | 9 km |
| Jul 14, 1992 | 6 km S of Walla Walla East, Washington | M4.1 | 139 km | 11 km |
| Oct 27, 1994 | 11 km SE of Halfway, Oregon | M4.0 | 95 km | 10 km |
| Jan 23, 2015 | 3 km N of Cayuse, Oregon | M3.5 | 111 km | 20 km |
| Dec 24, 1999 | 18 km WNW of New Meadows, Idaho | M3.5 | 140 km | 3 km |
| Jun 16, 1992 | 10 km ESE of Halfway, Oregon | M3.3 | 96 km | 5 km |
| Aug 27, 2000 | 16 km W of Richland, Oregon | M3.3 | 65 km | 0 km |
| Dec 15, 1991 | 6 km SSW of Walla Walla East, Washington | M3.3 | 140 km | 8 km |
| Jul 20, 1998 | 9 km ESE of Halfway, Oregon | M3.3 | 95 km | 12 km |
| Jan 26, 1992 | 28 km ENE of Halfway, Oregon | M3.2 | 114 km | 5 km |
| Jul 19, 1998 | 10 km ESE of Halfway, Oregon | M3.2 | 95 km | 11 km |
| Nov 23, 2001 | 6 km WNW of New Meadows, Idaho | M3.2 | 147 km | 0 km |
| Jul 25, 2009 | 10 km NW of Brogan, Oregon | M3.2 | 67 km | 7 km |
| Aug 14, 2017 | 19 km NNW of Halfway, Oregon | M3.1 | 84 km | 8 km |
| Oct 1, 2003 | 25 km W of Richland, Oregon | M3.1 | 56 km | 21 km |
| Jul 13, 2000 | 7 km NW of Unity, Oregon | M3.1 | 30 km | 19 km |
| Oct 17, 1993 | 33 km SE of Prairie City, Oregon | M3.1 | 63 km | 13 km |
| Jul 21, 1998 | 6 km N of Halfway, Oregon | M3.1 | 87 km | -1 km |
| Jul 20, 1998 | 10 km ESE of Halfway, Oregon | M3.1 | 95 km | 11 km |
| Oct 25, 1994 | 9 km ESE of Halfway, Oregon | M3.1 | 94 km | 10 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Tornado History
9 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF1.
| Date | Rating | Distance | Path | Fatalities |
| Jul 19, 2004 | EF1 | 81 km | 2.2 mi | 0 |
| Nov 5, 2023 | EF0 | 68 km | 0.2 mi | 0 |
| Jun 23, 2004 | EF0 | 33 km | 0.1 mi | 0 |
| Oct 4, 2003 | EF0 | 76 km | 0.2 mi | 0 |
| Apr 30, 1997 | EF0 | 90 km | 1.0 mi | 0 |
| May 17, 1996 | EF0 | 88 km | 0.1 mi | 0 |
| May 11, 1995 | EF0 | 30 km | 0.1 mi | 0 |
| Jun 21, 1983 | EF0 | 71 km | 0.1 mi | 0 |
| Sep 16, 1975 | EF0 | 31 km | 0.1 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Nearby Volcanoes
2 volcanoes within 200 km. Closest: Jordan Craters (187 km).
| Name | Type | Elevation | Last Eruption | Distance |
| Jordan Craters | Volcanic field | 1,473 m (4,833 ft) | -1250 | 187 km |
| Diamond Craters | Volcanic field | 1,435 m (4,708 ft) | -5610 | 188 km |
Source: Smithsonian Institution Global Volcanism Program (GVP).
Wildfire History
20 wildfires (100+ acres) recorded within 100 km. Largest: BATTLE MOUNTAIN COMPLEX (184,979 acres, 2024).
| Year | Name | Acres Burned | Distance |
| 2024 | BATTLE MOUNTAIN COMPLEX | 184,979 | 89 km |
| 2024 | COW VALLEY | 134,642 | 78 km |
| 2015 | CANYON CREEK COMPLEX | 109,786 | 71 km |
| 2015 | CORNET-WINDY RIDGE | 102,553 | 41 km |
| 2007 | MONUMENT COMPLEX (RED HILL FIRE) | 54,572 | 98 km |
| 1996 | TOWER | 50,827 | 51 km |
| 2015 | BENDIRE COMPLEX | 49,260 | 82 km |
| 2007 | IRISH SPRING | 47,845 | 62 km |
| 2020 | INDIAN CREEK | 46,275 | 96 km |
| 2016 | RAIL | 43,813 | 46 km |
| 2022 | WILLOW CREEK | 38,585 | 98 km |
| 1996 | BULL COMPLEX (SUMMIT) | 36,318 | 40 km |
| 2024 | THOMPSON | 31,066 | 68 km |
| 2001 | MONUMENT COMPLEX (MALLORY) | 29,095 | 93 km |
| 2021 | BLACK BUTTE | 24,736 | 71 km |
| 2005 | SNAKE ONE | 24,056 | 90 km |
| 2002 | MONUMENT-MALHEUR COMPLEX (MONUMENT) | 23,860 | 51 km |
| 2024 | COYOTE | 21,880 | 85 km |
| 2022 | STURGILL | 21,641 | 80 km |
| 2015 | ELDORADO | 20,962 | 47 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 29°F (-2°C) | 2.4 in | |
| February | 34°F (1°C) | 1.7 in | |
| March | 41°F (5°C) | 1.5 in | |
| April | 46°F (8°C) | 1.5 in | |
| May | 54°F (12°C) | 2.0 in | |
| June | 61°F (16°C) | 1.7 in | |
| July | 69°F (20°C) | 0.9 in | Warmest |
| August | 68°F (20°C) | 0.6 in | |
| September | 59°F (15°C) | 0.5 in | Driest |
| October | 47°F (8°C) | 1.5 in | |
| November | 36°F (2°C) | 2.3 in | |
| December | 29°F (-2°C) | 2.7 in | Coldest, Wettest |
Sumpter has a seasonal temperature swing of 40°F / from 29°F in December to 69°F in July. Total annual precipitation is 19.3 inches, with December being the wettest month (2.7") and September the driest (0.5").