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Weather & Climate in Mertzon, TX
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Mertzon enjoys a temperate climate with an average annual temperature of 64°F (18°C). Winters average 44°F in January while summers reach 82°F in July. The area gets 328 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 21.6 inches (drier than the 38-inch national average). Air quality is rated Good with a median AQI of 42. The city sits at an elevation of 2,211 feet.
Temperature
44°F Jan (7°C)
82°F Jul (28°C)
| Annual Average | 63.9°F |
| 18% above US avg | |
| January Average | 44°F (7°C) |
| July Average | 82°F (28°C) |
| Sunny Days | 328 days/yr |
Geography
| Elevation | 2,211 ft (674 m) |
| Area | 1.5 sq mi (3.9 km²) |
| Population Density | 539/sq mi |
| Coordinates | 31.2620°N, 100.8208°W |
| Timezone | America/Chicago |
| County | Irion County County |
| Nearest Airport | San Angelo Regional/Mathis Field (SJT) 20 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 42.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Very Low |
| Risk Score | 1.8 / 100 |
| Social Vulnerability | 71.7 / 100 |
| Community Resilience | 15.3 / 100 |
Hazard Breakdown
| Tornado | Very Low |
| Hurricane | Very Low |
| Earthquake | Very Low |
| Wildfire | Relatively Low |
| Flood | Very Low |
| Hail | Very Low |
| Strong Wind | Very Low |
| Heat Wave | Very Low |
| Winter Weather | Very Low |
| Lightning | Very Low |
| Ice Storm | Very Low |
| Drought | Relatively Low |
| Cold Wave | Very Low |
| Landslide | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
111 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M3.9.
| Jun 6, 2022 | 18 km SE of Ackerly, Texas | M3.9 | 146 km | 7 km |
| Aug 15, 2024 | 28 km SW of Garden City, Texas | M3.8 | 96 km | 8 km |
| Jun 16, 2022 | 16 km SSE of Ackerly, Texas | M3.6 | 148 km | 8 km |
| Aug 10, 2024 | 28 km SW of Garden City, Texas | M3.6 | 97 km | 6 km |
| Jul 19, 2024 | 6 km WSW of Westbrook, Texas | M3.6 | 121 km | 9 km |
| Feb 15, 2021 | 15 km N of Stanton, Texas | M3.5 | 145 km | 5 km |
| Jul 31, 2023 | 17 km SSE of Ackerly, Texas | M3.5 | 147 km | 6 km |
| Mar 19, 2022 | 18 km SSE of Ackerly, Texas | M3.5 | 146 km | 4 km |
| Aug 12, 2022 | 16 km SE of Ackerly, Texas | M3.4 | 148 km | 6 km |
| Jan 1, 2021 | 17 km N of Stanton, Texas | M3.4 | 146 km | 5 km |
| Apr 3, 2025 | 28 km SW of Garden City, Texas | M3.4 | 99 km | 10 km |
| Feb 10, 2022 | 24 km W of Garden City, Texas | M3.3 | 111 km | 9 km |
| Jul 25, 2022 | 18 km SSE of Ackerly, Texas | M3.3 | 146 km | 8 km |
| Aug 23, 2024 | 28 km SW of Garden City, Texas | M3.3 | 97 km | 9 km |
| Jun 26, 2024 | 24 km SSW of Westbrook, Texas | M3.3 | 101 km | 8 km |
| Jun 10, 2022 | 19 km N of Stanton, Texas | M3.3 | 148 km | 8 km |
| Jun 23, 2024 | 26 km WNW of Robert Lee, Texas | M3.3 | 84 km | 9 km |
| Jul 29, 2023 | 17 km SSE of Ackerly, Texas | M3.3 | 147 km | 9 km |
| Mar 19, 2022 | 17 km SSE of Ackerly, Texas | M3.2 | 147 km | 5 km |
| Jan 2, 2022 | 17 km N of Stanton, Texas | M3.2 | 145 km | 8 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
210 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 15 fatalities, 199 injuries.
| Date | Rating | Distance | Path | Fatalities |
| May 11, 1953 | EF4 | 38 km | 9.9 mi | 13 |
| May 22, 2024 | EF3 | 45 km | 4.8 mi | 0 |
| May 3, 2024 | EF3 | 71 km | 3.5 mi | 0 |
| May 18, 2019 | EF3 | 75 km | 18.0 mi | 0 |
| May 22, 2016 | EF3 | 99 km | 3.7 mi | 0 |
| May 14, 1995 | EF3 | 68 km | 5.0 mi | 0 |
| Mar 14, 1982 | EF3 | 93 km | 40.5 mi | 0 |
| Apr 30, 1952 | EF3 | 39 km | 0.5 mi | 0 |
| May 3, 2024 | EF2 | 86 km | 4.5 mi | 0 |
| May 17, 2021 | EF2 | 94 km | 11.4 mi | 0 |
| May 18, 2019 | EF2 | 18 km | 17.6 mi | 0 |
| May 18, 2019 | EF2 | 33 km | 2.1 mi | 0 |
| Oct 13, 2018 | EF2 | 18 km | 3.0 mi | 0 |
| Mar 28, 2017 | EF2 | 93 km | 1.8 mi | 0 |
| May 22, 2016 | EF2 | 95 km | 1.9 mi | 0 |
| Mar 22, 2000 | EF2 | 80 km | 12.0 mi | 0 |
| May 4, 1999 | EF2 | 36 km | 23.0 mi | 0 |
| May 14, 1989 | EF2 | 46 km | 6.0 mi | 0 |
| Sep 27, 1976 | EF2 | 97 km | 0.1 mi | 0 |
| Apr 15, 1976 | EF2 | 85 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: GLASS (196,945 acres, 2008).
| Year | Name | Acres Burned | Distance |
| 2008 | GLASS | 196,945 | 47 km |
| 2011 | WILDCAT | 150,157 | 62 km |
| 2006 | COLE | 39,436 | 47 km |
| 2006 | ROCKER B | 37,361 | 44 km |
| 2011 | WILLIAMS | 23,912 | 48 km |
| 2011 | DOS AMIGOS | 18,960 | 81 km |
| 2008 | SILVER | 18,094 | 85 km |
| 2012 | WILDCAT | 14,034 | 64 km |
| 2011 | ENCINO | 12,156 | 30 km |
| 2011 | SCOTT RANCH | 10,755 | 26 km |
| 1993 | MENARD FIRE | 10,463 | 87 km |
| 2015 | FORT MCKAVETT COMPLEX | 8,225 | 93 km |
| 2019 | 190 EAST | 7,091 | 47 km |
| 2008 | UNNAMED | 6,810 | 65 km |
| 2022 | CHICO LANE | 6,617 | 53 km |
| 2019 | 7D | 5,402 | 41 km |
| 2020 | 7D2 | 5,253 | 53 km |
| 2015 | HEAD OF THE RIVER RANCH | 5,205 | 39 km |
| 2019 | OGLESBY | 5,098 | 40 km |
| 2020 | ARROYO GRANDE | 4,855 | 70 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 44°F (7°C) | 0.8 in | Coldest, Driest |
| February | 49°F (9°C) | 1.2 in | |
| March | 56°F (14°C) | 1.0 in | |
| April | 65°F (18°C) | 1.6 in | |
| May | 73°F (23°C) | 3.0 in | |
| June | 79°F (26°C) | 2.3 in | |
| July | 82°F (28°C) | 1.5 in | Warmest |
| August | 81°F (27°C) | 2.4 in | |
| September | 74°F (24°C) | 3.3 in | Wettest |
| October | 65°F (18°C) | 2.2 in | |
| November | 54°F (12°C) | 1.1 in | |
| December | 46°F (8°C) | 0.9 in |
Mertzon has a seasonal temperature swing of 38°F / from 44°F in January to 82°F in July. Total annual precipitation is 21.1 inches, with September being the wettest month (3.3") and January the driest (0.8").