Weather & Climate in Byron, WY
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Byron has a cool climate with an average annual temperature of 45°F (7°C). Winters average 19°F in January while summers reach 71°F in July. Annual precipitation totals 6.5 inches (drier than the 38-inch national average). The area receives 13.3 inches of snow annually. Air quality is rated Good with a median AQI of 39. 89% of days have good air quality. The city sits at an elevation of 4,032 feet.
Temperature
19°F Jan (-7°C)
71°F Jul (22°C)
| Annual Average | 44.9°F |
| 17% below US avg | |
| January Average | 19°F (-7°C) |
| July Average | 71°F (22°C) |
Geography
| Elevation | 4,032 ft (1,229 m) |
| Area | 1.0 sq mi (2.5 km²) |
| Population Density | 511/sq mi |
| Coordinates | 44.7967°N, 108.5085°W |
| Timezone | America/Denver |
| County | Big Horn County County |
| Nearest Airport | Yellowstone Regional (COD) 32 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 39.0 |
| Rating | Good |
| Good Days % | 89.2% |
| Unhealthy Days | 2 |
Natural Hazard Risk
| Overall Risk | Very Low |
| Risk Score | 31.1 / 100 |
| Social Vulnerability | 52.6 / 100 |
| Community Resilience | 7.7 / 100 |
Hazard Breakdown
| Tornado | Very Low |
| Earthquake | Relatively Low |
| Wildfire | Very Low |
| Flood | Relatively Low |
| Hail | Very Low |
| Strong Wind | Very Low |
| Heat Wave | Very Low |
| Winter Weather | Relatively Low |
| Lightning | Relatively Low |
| Ice Storm | Very Low |
| Drought | Relatively Low |
| Cold Wave | Relatively Low |
| Landslide | Relatively High |
| Volcano | Very Low |
| Avalanche | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
99 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.2.
| May 11, 2022 | 36 km S of Silver Gate, Montana | M4.2 | 118 km | 14 km |
| Mar 25, 2008 | 35 km S of Silver Gate, Montana | M4.2 | 120 km | 4 km |
| Mar 29, 2023 | 56 km SSE of Mammoth, Wyoming | M3.7 | 150 km | 4 km |
| Jul 17, 2021 | 63 km SSE of Mammoth, Wyoming | M3.6 | 150 km | 6 km |
| Jul 20, 1992 | 52 km SSE of Mammoth, Wyoming | M3.6 | 148 km | 0 km |
| Jul 20, 1992 | 51 km SSE of Mammoth, Wyoming | M3.5 | 149 km | 2 km |
| Aug 7, 1991 | 31 km NNW of Pavillion, Wyoming | M3.5 | 147 km | 5 km |
| Jan 9, 2007 | 7 km ENE of East Thermopolis, Wyoming | M3.5 | 130 km | 5 km |
| Nov 16, 1993 | 17 km SSE of Ten Sleep, Wyoming | M3.5 | 135 km | 5 km |
| Jan 2, 2009 | 54 km SSE of Mammoth, Wyoming | M3.5 | 149 km | 7 km |
| Mar 4, 2019 | 35 km SSW of Silver Gate, Montana | M3.3 | 125 km | 6 km |
| Apr 5, 2002 | 7 km W of South Flat, Wyoming | M3.3 | 100 km | 5 km |
| Jan 9, 2009 | 42 km SSW of Silver Gate, Montana | M3.3 | 138 km | 7 km |
| Aug 16, 1992 | 47 km S of Silver Gate, Montana | M3.2 | 120 km | 5 km |
| Jul 21, 2023 | Eastern Montana | M3.2 | 83 km | 5 km |
| Jul 3, 1994 | 25 km ESE of Mammoth, Wyoming | M3.2 | 150 km | 11 km |
| Nov 9, 2009 | 40 km SW of Silver Gate, Montana | M3.1 | 140 km | 6 km |
| Dec 16, 2012 | 40 km W of Owl Creek, Wyoming | M3.1 | 121 km | 5 km |
| Jan 2, 2009 | 52 km SSE of Mammoth, Wyoming | M3.1 | 150 km | 3 km |
| Mar 29, 2023 | Wyoming | M3.1 | 149 km | 3 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Tornado History
47 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF3. Total: 1 fatality, 2 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Aug 2, 1985 | EF3 | 44 km | 0.2 mi | 0 |
| Jun 16, 2010 | EF2 | 45 km | 1.0 mi | 0 |
| Jul 11, 1978 | EF2 | 29 km | 0.4 mi | 0 |
| Jul 4, 1978 | EF2 | 52 km | 5.0 mi | 0 |
| Jul 24, 1967 | EF2 | 55 km | 0.1 mi | 0 |
| Jun 26, 1964 | EF2 | 20 km | 1.0 mi | 0 |
| Jul 9, 1962 | EF2 | 52 km | 0.5 mi | 0 |
| Jun 12, 1962 | EF2 | 36 km | 0.5 mi | 0 |
| Jun 26, 1959 | EF2 | 83 km | 9.2 mi | 1 |
| Jun 3, 1958 | EF2 | 65 km | 0.2 mi | 0 |
| Jun 1, 2009 | EF1 | 83 km | 0.4 mi | 0 |
| Jun 26, 2001 | EF1 | 51 km | 0.7 mi | 0 |
| Jun 6, 1997 | EF1 | 44 km | 1.0 mi | 0 |
| May 18, 1991 | EF1 | 33 km | 0.2 mi | 0 |
| May 24, 1990 | EF1 | 38 km | 0.2 mi | 0 |
| Aug 25, 1986 | EF1 | 48 km | 1.0 mi | 0 |
| Jun 15, 1984 | EF1 | 90 km | 1.0 mi | 0 |
| Jul 24, 1981 | EF1 | 11 km | 0.1 mi | 0 |
| Jun 18, 1978 | EF1 | 21 km | 0.1 mi | 0 |
| Jul 4, 1976 | EF1 | 60 km | 0.2 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Nearby Volcanoes
1 volcano within 200 km. Closest: Yellowstone (176 km).
| Name | Type | Elevation | Last Eruption | Distance |
| Yellowstone | Caldera(s) | 2,805 m (9,203 ft) | -1350 | 176 km |
Source: Smithsonian Institution Global Volcanism Program (GVP).
Wildfire History
20 wildfires (100+ acres) recorded within 100 km. Largest: GUNBARREL (69,730 acres, 2008).
| Year | Name | Acres Burned | Distance |
| 2008 | GUNBARREL | 69,730 | 81 km |
| 2018 | TEREK | 43,872 | 90 km |
| 2021 | ROBERTSON DRAW | 31,132 | 63 km |
| 1996 | SHEPARD MTN | 17,379 | 98 km |
| 2007 | BONE CREEK | 12,776 | 70 km |
| 2016 | WHIT | 12,731 | 80 km |
| 2008 | CASCADE | 10,017 | 86 km |
| 1999 | ROOSTER | 9,624 | 91 km |
| 2021 | CRATER RIDGE | 8,147 | 62 km |
| 2011 | HOLE IN THE WALL | 6,559 | 69 km |
| 2006 | BIRTHDAY2 | 6,553 | 85 km |
| 2003 | LITTLE HORN II | 5,889 | 67 km |
| 2003 | DEEP LAKE | 5,466 | 66 km |
| 2002 | COW CREEK | 5,162 | 96 km |
| 2002 | RED WAFFLE | 5,060 | 35 km |
| 2005 | BIG HORN | 4,899 | 50 km |
| 1991 | ROBERTSON | 4,812 | 62 km |
| 2000 | MIDDLECREE | 4,534 | 98 km |
| 2021 | CROOKED CREEK | 4,295 | 46 km |
| 1994 | UNNAMED | 3,981 | 50 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 19°F (-7°C) | 0.2 in | Coldest, Driest |
| February | 24°F (-4°C) | 0.3 in | |
| March | 36°F (2°C) | 0.2 in | |
| April | 45°F (7°C) | 0.7 in | |
| May | 54°F (12°C) | 1.1 in | |
| June | 64°F (18°C) | 1.2 in | Wettest |
| July | 71°F (22°C) | 0.6 in | Warmest |
| August | 69°F (20°C) | 0.3 in | |
| September | 59°F (15°C) | 0.8 in | |
| October | 45°F (7°C) | 0.7 in | |
| November | 32°F (0°C) | 0.2 in | |
| December | 21°F (-6°C) | 0.2 in |
Byron has a seasonal temperature swing of 52°F / from 19°F in January to 71°F in July. Total annual precipitation is 6.5 inches, with June being the wettest month (1.2") and January the driest (0.2").