All Countries
Weather & Climate in Darby, MT
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Darby has a cool climate with an average annual temperature of 45°F (7°C). Winters average 27°F in January while summers reach 66°F in July. The area gets 273 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 15.1 inches (drier than the 38-inch national average). Air quality is rated Good with a median AQI of 26 / among the cleanest air in the country. The city sits at an elevation of 3,890 feet.
Temperature
27°F Jan (-3°C)
66°F Jul (19°C)
| Annual Average | 44.6°F |
| 17% below US avg | |
| January Average | 27°F (-3°C) |
| July Average | 66°F (19°C) |
| Sunny Days | 273 days/yr |
Geography
| Elevation | 3,890 ft (1,186 m) |
| Area | 0.6 sq mi (1.5 km²) |
| Population Density | 858/sq mi |
| Coordinates | 46.0245°N, 114.1797°W |
| Timezone | America/Denver |
| County | Ravalli County County |
| Nearest Airport | Missoula Montana (MSO) 62 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 26.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 78.5 / 100 |
| Social Vulnerability | 45.2 / 100 |
| Community Resilience | 27.3 / 100 |
Hazard Breakdown
| Tornado | Very Low |
| Earthquake | Relatively Low |
| Wildfire | Relatively High |
| Flood | Relatively Low |
| Hail | Very Low |
| Strong Wind | Very Low |
| Heat Wave | Relatively Low |
| Winter Weather | Relatively High |
| Lightning | Relatively Moderate |
| Ice Storm | Relatively Moderate |
| Drought | Very Low |
| Cold Wave | Relatively Moderate |
| Landslide | Relatively Moderate |
| Avalanche | Relatively High |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
183 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M5.6.
| Jul 26, 2005 | 16 km N of Dillon, Montana | M5.6 | 142 km | 13 km |
| Jul 6, 2017 | 15 km S of Lincoln, Montana | M5.0 | 146 km | 15 km |
| Jul 27, 2005 | 18 km N of Dillon, Montana | M4.0 | 142 km | 5 km |
| Jun 28, 2000 | 21 km SE of Clinton, Montana | M4.0 | 83 km | 10 km |
| Jan 18, 2006 | 18 km NNE of Dillon, Montana | M4.0 | 149 km | 9 km |
| Jul 28, 2014 | 13 km N of Dillon, Montana | M3.9 | 144 km | 10 km |
| Mar 13, 2017 | 4 km ESE of Avon, Montana | M3.8 | 139 km | 20 km |
| Jun 4, 2006 | 18 km N of Dillon, Montana | M3.8 | 142 km | 11 km |
| Jul 26, 2005 | 21 km N of Dillon, Montana | M3.8 | 140 km | 5 km |
| Nov 8, 1997 | 39 km SE of Pierce, Idaho | M3.8 | 99 km | 5 km |
| Feb 3, 2019 | 9 km S of Lincoln, Montana | M3.7 | 149 km | 5 km |
| May 30, 1992 | 54 km NNW of Challis, Idaho | M3.7 | 128 km | 5 km |
| Mar 29, 2007 | 14 km NNE of Dillon, Montana | M3.7 | 146 km | 13 km |
| Aug 6, 2023 | 37 km NNW of Challis, Idaho | M3.6 | 135 km | 15 km |
| Jan 7, 2018 | 13 km SSW of Lincoln, Montana | M3.6 | 143 km | 9 km |
| Jan 13, 1998 | 26 km WNW of Leadore, Idaho | M3.6 | 146 km | 5 km |
| Apr 24, 1996 | 27 km NNE of Challis, Idaho | M3.6 | 142 km | 5 km |
| Aug 7, 2005 | 18 km NNE of Dillon, Montana | M3.6 | 145 km | 5 km |
| Sep 15, 1998 | 9 km ENE of Ovando, Montana | M3.6 | 146 km | 6 km |
| Jul 29, 2005 | 21 km N of Dillon, Montana | M3.5 | 140 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
13 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF2. Total: 1 injury.
| Date | Rating | Distance | Path | Fatalities |
| Jun 23, 1975 | EF2 | 21 km | 0.1 mi | 0 |
| Jun 14, 1962 | EF2 | 92 km | 0.1 mi | 0 |
| Jul 3, 1988 | EF1 | 94 km | 0.2 mi | 0 |
| Jun 15, 1987 | EF1 | 98 km | 0.1 mi | 0 |
| Jun 6, 1976 | EF1 | 96 km | 3.0 mi | 0 |
| Jun 1, 1956 | EF1 | 94 km | 0.5 mi | 0 |
| Aug 20, 2018 | EF0 | 74 km | 0.8 mi | 0 |
| May 16, 1991 | EF0 | 61 km | 0.2 mi | 0 |
| Aug 15, 1990 | EF0 | 46 km | 0.1 mi | 0 |
| Oct 16, 1988 | EF0 | 25 km | 0.2 mi | 0 |
| Aug 11, 1988 | EF0 | 87 km | 2.0 mi | 0 |
| Jul 20, 1983 | EF0 | 98 km | 2.0 mi | 0 |
| Jul 14, 1962 | EF0 | 92 km | 0.1 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Wildfire History
20 wildfires (100+ acres) recorded within 100 km. Largest: MUSTANG COMPLEX (377,632 acres, 2012).
| Year | Name | Acres Burned | Distance |
| 2012 | MUSTANG COMPLEX | 377,632 | 66 km |
| 2000 | CLEAR CREEK DIVIDE COMPLEX (CLEAR CREEK) | 170,322 | 93 km |
| 2022 | MOOSE | 142,221 | 80 km |
| 2000 | VALLEY COMPLEX (BEAR) | 118,045 | 8 km |
| 2017 | MEYERS | 68,711 | 49 km |
| 2007 | SAWMILL COMPLEX (WYMAN 2) | 68,236 | 64 km |
| 2000 | MUSSIGBROD COMPLEX (MUSSIGBROD) | 64,810 | 46 km |
| 2000 | SULA COMPLEX (MAYNARD) | 62,967 | 30 km |
| 2021 | TRAIL CREEK | 62,432 | 55 km |
| 2017 | LOLO PEAK | 62,316 | 72 km |
| 2007 | KRASSEL COMPLEX (TAG WFU) | 49,358 | 91 km |
| 2012 | PORCUPINE COMPLEX | 48,980 | 70 km |
| 2013 | GOLD PAN COMPLEX | 43,216 | 52 km |
| 1988 | LADDER | 42,348 | 90 km |
| 1996 | SWET-WARRIOR COMPLEX (SWET CREEK) | 39,495 | 64 km |
| 2015 | WASH | 39,448 | 90 km |
| 2021 | ALDER CREEK | 38,189 | 83 km |
| 2007 | BRIDGE | 36,732 | 47 km |
| 2017 | LITTLE HOGBACK | 34,646 | 63 km |
| 2011 | SADDLE COMPLEX | 30,877 | 59 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 27°F (-3°C) | 1.4 in | |
| February | 28°F (-3°C) | 0.9 in | Driest |
| March | 33°F (0°C) | 1.0 in | |
| April | 39°F (4°C) | 1.1 in | |
| May | 47°F (8°C) | 2.0 in | Wettest |
| June | 55°F (13°C) | 1.9 in | |
| July | 66°F (19°C) | 1.0 in | Warmest |
| August | 61°F (16°C) | 1.3 in | |
| September | 52°F (11°C) | 1.3 in | |
| October | 42°F (6°C) | 1.0 in | |
| November | 30°F (-1°C) | 1.2 in | |
| December | 23°F (-5°C) | 1.3 in | Coldest |
Darby has a seasonal temperature swing of 43°F / from 23°F in December to 66°F in July. Total annual precipitation is 15.4 inches, with May being the wettest month (2.0") and February the driest (0.9").