Weather & Climate in Sweetwater, ID
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Sweetwater experiences four distinct seasons with an average annual temperature of 54°F (12°C). Winters average 36°F in January while summers reach 76°F in July. Annual precipitation totals 12.9 inches (drier than the 38-inch national average). The area receives 12.7 inches of snow annually. Air quality is rated Good with a median AQI of 29 / among the cleanest air in the country. 75% of days have good air quality. The city sits at an elevation of 1,117 feet.
Temperature
36°F Jan (2°C)
76°F Jul (24°C)
| Annual Average | 53.8°F |
| 0% below US avg | |
| January Average | 36°F (2°C) |
| July Average | 76°F (24°C) |
Geography
| Elevation | 1,117 ft (340 m) |
| Area | 1.2 sq mi (3.1 km²) |
| Population Density | 141/sq mi |
| Coordinates | 46.3676°N, 116.7975°W |
| Timezone | America/Boise |
| County | Nez Perce County County |
| Nearest Airport | Pullman/Moscow Regional (PUW) 30 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 29.0 |
| Rating | Good |
| Good Days % | 75.4% |
| Unhealthy Days | 8 |
Natural Hazard Risk
| Overall Risk | Very Low |
| Risk Score | 33.0 / 100 |
| Social Vulnerability | 10.6 / 100 |
| Community Resilience | 55.3 / 100 |
Hazard Breakdown
| Tornado | Very Low |
| Earthquake | Very Low |
| Wildfire | Relatively Moderate |
| Flood | Relatively Low |
| Hail | Very Low |
| Strong Wind | Very Low |
| Heat Wave | Relatively Low |
| Winter Weather | Very Low |
| Lightning | Very Low |
| Ice Storm | Very Low |
| Drought | Very Low |
| Cold Wave | Very Low |
| Landslide | Very Low |
| Avalanche | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
88 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 | 124 km | 9 km |
| Jul 14, 1992 | 6 km S of Walla Walla East, Washington | M4.1 | 124 km | 11 km |
| Aug 17, 1994 | 1 km E of Mullan, Idaho | M4.1 | 145 km | 2 km |
| Nov 8, 1997 | 39 km SE of Pierce, Idaho | M3.8 | 107 km | 5 km |
| Jun 28, 1998 | 3 km SE of Genesee, Idaho | M3.8 | 20 km | 10 km |
| May 30, 1996 | 3 km SSW of Mullan, Idaho | M3.6 | 141 km | 1 km |
| Mar 14, 1997 | 1 km E of Mullan, Idaho | M3.6 | 145 km | 2 km |
| Dec 24, 1999 | 18 km WNW of New Meadows, Idaho | M3.5 | 148 km | 3 km |
| Mar 8, 1994 | 32 km S of Wallace, Idaho | M3.4 | 112 km | 5 km |
| Jun 17, 2004 | 11 km SSE of Washtucna, Washington | M3.4 | 115 km | 17 km |
| Jun 28, 1997 | 3 km NNW of Mullan, Idaho | M3.4 | 147 km | 2 km |
| May 10, 2000 | Idaho-Montana border region | M3.3 | 145 km | 2 km |
| Dec 15, 1991 | 6 km SSW of Walla Walla East, Washington | M3.3 | 125 km | 8 km |
| Feb 11, 2025 | 2 km NNW of Mullan, Idaho | M3.3 | 146 km | 5 km |
| Feb 9, 1996 | 2 km W of Mullan, Idaho | M3.2 | 143 km | 1 km |
| Feb 10, 2013 | 29 km ESE of Pierce, Idaho | M3.2 | 102 km | 5 km |
| Jan 26, 1992 | 28 km ENE of Halfway, Oregon | M3.2 | 150 km | 5 km |
| May 6, 2004 | 0 km W of Mullan, Idaho | M3.1 | 144 km | 2 km |
| Mar 12, 1999 | 17 km NW of Malden, Washington | M3.1 | 125 km | 5 km |
| Jun 12, 1999 | 0 km E of Mullan, Idaho | M3.1 | 145 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Tornado History
17 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF2.
| Date | Rating | Distance | Path | Fatalities |
| Aug 30, 1971 | EF2 | 75 km | 0.5 mi | 0 |
| Jun 11, 1968 | EF2 | 73 km | 9.6 mi | 0 |
| Mar 14, 1966 | EF2 | 78 km | 1.0 mi | 0 |
| May 8, 1962 | EF2 | 4 km | 9.1 mi | 0 |
| Jan 16, 2000 | EF1 | 93 km | 1.0 mi | 0 |
| May 19, 1986 | EF1 | 43 km | 2.0 mi | 0 |
| May 2, 1973 | EF1 | 43 km | 0.1 mi | 0 |
| Jun 20, 1969 | EF1 | 15 km | 1.0 mi | 0 |
| Jul 12, 2016 | EF0 | 98 km | 1.0 mi | 0 |
| Oct 7, 2010 | EF0 | 39 km | 1.0 mi | 0 |
| Oct 7, 2010 | EF0 | 39 km | 0.4 mi | 0 |
| Jun 29, 2007 | EF0 | 67 km | 0.3 mi | 0 |
| May 31, 1997 | EF0 | 15 km | 0.1 mi | 0 |
| Jun 1, 1991 | EF0 | 20 km | 0.1 mi | 0 |
| May 1, 1991 | EF0 | 22 km | 0.1 mi | 0 |
| Sep 14, 1986 | EF0 | 82 km | 0.2 mi | 0 |
| Apr 11, 1979 | EF0 | 72 km | 1.0 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Wildfire History
20 wildfires (100+ acres) recorded within 100 km. Largest: DOUBLE CREEK (171,012 acres, 2022).
| Year | Name | Acres Burned | Distance |
| 2022 | DOUBLE CREEK | 171,012 | 95 km |
| 2000 | MALONEY CREEK | 131,397 | 48 km |
| 2006 | COLUMBIA COMPLEX | 118,865 | 81 km |
| 2021 | SHOVEL CREEK | 109,829 | 38 km |
| 2021 | LICK CREEK | 80,376 | 50 km |
| 2015 | BUTTE CREEK | 79,418 | 74 km |
| 2012 | CACHE CREEK | 75,521 | 52 km |
| 2014 | BIG COUGAR | 65,397 | 41 km |
| 2007 | POE CABIN | 59,704 | 87 km |
| 1988 | TEEPEE BUTTE | 59,565 | 57 km |
| 2005 | SCHOOL | 51,701 | 64 km |
| 2007 | CHIMNEY COMPLEX | 50,646 | 36 km |
| 1996 | SALT COMPLEX (SALT CREEK) | 50,250 | 92 km |
| 2015 | KAMIAH GULCH | 48,459 | 59 km |
| 2017 | POWERLINE | 45,449 | 44 km |
| 2021 | GREEN RIDGE | 44,604 | 69 km |
| 1986 | JOSEPH/STARVATION | 37,064 | 67 km |
| 2014 | SOMERS | 36,374 | 89 km |
| 2000 | EASTSIDE COMPLEX (DEEP CREEK) | 31,969 | 71 km |
| 2000 | BURNT FLATS | 24,808 | 81 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 36°F (2°C) | 1.1 in | |
| February | 39°F (4°C) | 1.0 in | |
| March | 45°F (7°C) | 1.3 in | |
| April | 52°F (11°C) | 1.4 in | |
| May | 60°F (16°C) | 1.7 in | Wettest |
| June | 67°F (19°C) | 1.3 in | |
| July | 76°F (24°C) | 0.5 in | Warmest, Driest |
| August | 75°F (24°C) | 0.5 in | |
| September | 66°F (19°C) | 0.6 in | |
| October | 53°F (11°C) | 1.1 in | |
| November | 42°F (5°C) | 1.2 in | |
| December | 35°F (2°C) | 1.1 in | Coldest |
Sweetwater has a seasonal temperature swing of 41°F / from 35°F in December to 76°F in July. Total annual precipitation is 12.9 inches, with May being the wettest month (1.7") and July the driest (0.5").