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Weather & Climate in Duncan, OK
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Duncan enjoys a temperate climate with an average annual temperature of 64°F (18°C). Winters average 43°F in January while summers reach 85°F in July. The area gets 320 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 32.2 inches. The area receives 1.9 inches of snow annually. Air quality is rated Good with a median AQI of 45. The city sits at an elevation of 1,113 feet.
Temperature
43°F Jan (6°C)
85°F Jul (29°C)
| Annual Average | 64.2°F |
| 19% above US avg | |
| January Average | 43°F (6°C) |
| July Average | 85°F (29°C) |
| Sunny Days | 320 days/yr |
Geography
| Elevation | 1,113 ft (339 m) |
| Area | 47.7 sq mi (123.6 km²) |
| Population Density | 533/sq mi |
| Coordinates | 34.4816°N, 97.9605°W |
| Timezone | America/Chicago |
| County | Stephens County County |
| Nearest Airport | Lawton-Fort Sill Regional (LAW) 27 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 45.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 65.9 / 100 |
| Social Vulnerability | 52.8 / 100 |
| Community Resilience | 27.0 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Hurricane | Very Low |
| Earthquake | Relatively Low |
| Wildfire | Relatively Low |
| Flood | Relatively Low |
| Hail | Relatively Moderate |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Moderate |
| Winter Weather | Relatively Moderate |
| Lightning | Relatively Low |
| Ice Storm | Relatively High |
| Drought | Relatively Moderate |
| Cold Wave | Relatively Moderate |
| Landslide | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
1,045 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.5.
| Sep 6, 1997 | 6 km N of Tupelo, Oklahoma | M4.5 | 141 km | 5 km |
| Dec 7, 2013 | 8 km SW of Arcadia, Oklahoma | M4.5 | 136 km | 8 km |
| Jun 16, 2014 | 7 km NNE of Lake Aluma, Oklahoma | M4.3 | 134 km | 5 km |
| Jan 13, 2024 | 6 km W of Arcadia, Oklahoma | M4.3 | 141 km | 7 km |
| Jan 18, 1995 | 4 km SSE of Erin Springs, Oklahoma | M4.2 | 47 km | 5 km |
| Jan 1, 2016 | 6 km ENE of Edmond, Oklahoma | M4.2 | 141 km | 6 km |
| Apr 7, 2016 | 1 km E of Luther, Oklahoma | M4.2 | 150 km | 6 km |
| Aug 3, 2017 | 6 km ENE of Edmond, Oklahoma | M4.2 | 142 km | 5 km |
| Jun 18, 2014 | 7 km NE of Lake Aluma, Oklahoma | M4.1 | 134 km | 5 km |
| Jan 13, 2024 | 6 km ENE of Edmond, Oklahoma | M4.1 | 142 km | 7 km |
| Jun 20, 2015 | 9 km NW of Arcadia, Oklahoma | M4.0 | 149 km | 3 km |
| Nov 15, 1990 | 5 km SSE of Erin Springs, Oklahoma | M3.9 | 46 km | 5 km |
| Jul 15, 2014 | 3 km N of Harrah, Oklahoma | M3.9 | 137 km | 7 km |
| Apr 28, 1998 | 9 km NE of Medicine Park, Oklahoma | M3.9 | 53 km | 5 km |
| Jun 22, 2015 | 10 km NNW of Arcadia, Oklahoma | M3.9 | 150 km | 6 km |
| Jan 15, 2010 | 3 km ENE of Jones, Oklahoma | M3.8 | 138 km | 8 km |
| Feb 8, 2002 | 8 km SW of Elgin, Oklahoma | M3.8 | 46 km | 5 km |
| Nov 5, 2013 | 8 km SSW of Arcadia, Oklahoma | M3.8 | 136 km | 5 km |
| May 31, 2014 | 1 km ESE of Choctaw, Oklahoma | M3.7 | 130 km | 7 km |
| Mar 1, 2018 | 3 km NE of Arcadia, Oklahoma | M3.7 | 147 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
869 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF5. Total: 163 fatalities, 3,437 injuries.
| Date | Rating | Distance | Path | Fatalities |
| May 20, 2013 | EF5 | 94 km | 13.9 mi | 24 |
| May 3, 1999 | EF5 | 73 km | 37.0 mi | 36 |
| Apr 3, 1964 | EF5 | 82 km | 4.7 mi | 7 |
| Apr 27, 2024 | EF4 | 98 km | 26.8 mi | 1 |
| May 9, 2016 | EF4 | 56 km | 8.9 mi | 1 |
| May 24, 2011 | EF4 | 49 km | 23.1 mi | 0 |
| May 24, 2011 | EF4 | 59 km | 33.3 mi | 1 |
| May 10, 2010 | EF4 | 92 km | 22.3 mi | 1 |
| May 10, 2010 | EF4 | 99 km | 24.0 mi | 2 |
| Feb 10, 2009 | EF4 | 69 km | 37.0 mi | 8 |
| Apr 10, 1979 | EF4 | 97 km | 46.9 mi | 42 |
| Apr 17, 1976 | EF4 | 68 km | 32.9 mi | 0 |
| Apr 19, 1972 | EF4 | 39 km | 28.2 mi | 5 |
| May 26, 1962 | EF4 | 58 km | 10.1 mi | 0 |
| Sep 14, 1957 | EF4 | 83 km | 67.5 mi | 2 |
| May 24, 1957 | EF4 | 55 km | 21.6 mi | 4 |
| Nov 3, 2024 | EF3 | 21 km | 21.7 mi | 0 |
| Apr 27, 2024 | EF3 | 89 km | 9.9 mi | 1 |
| Apr 19, 2023 | EF3 | 73 km | 10.9 mi | 1 |
| May 9, 2016 | EF3 | 75 km | 16.6 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Wildfire History
20 wildfires (100+ acres) recorded within 100 km. Largest: LOCO-HEALDTON (56,584 acres, 2009).
| Year | Name | Acres Burned | Distance |
| 2009 | LOCO-HEALDTON | 56,584 | 51 km |
| 2011 | FERGUSON | 41,429 | 74 km |
| 1991 | ARBUCKLE | 29,823 | 75 km |
| 2021 | WINDMILL | 28,410 | 65 km |
| 2009 | MONTAGUE COUNTY COMPLEX | 25,907 | 91 km |
| 2012 | TOWNLEY ROAD | 24,139 | 84 km |
| 2009 | RATCLIFF CITY-TATUMS | 23,099 | 45 km |
| 2009 | TWO MILE HILL COMPLEX | 20,991 | 98 km |
| 2009 | BRUSHY MOUNTAIN | 18,412 | 76 km |
| 1996 | WESTSIDE | 16,723 | 83 km |
| 2006 | RINGGOLD | 16,382 | 75 km |
| 2005 | UNNAMED | 15,416 | 60 km |
| 1996 | HENRIETTA FIRE | 13,629 | 98 km |
| 2006 | RATLIFF CITY | 12,435 | 46 km |
| 2024 | RUSH | 12,239 | 68 km |
| 2011 | WICHITA COUNTY COMPLEX | 12,118 | 95 km |
| 2008 | UNNAMED | 10,392 | 54 km |
| 2000 | UNNAMED | 9,943 | 72 km |
| 2022 | 62 FIRE | 9,804 | 88 km |
| 1993 | CRATER CREEK | 8,963 | 61 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 43°F (6°C) | 1.2 in | Driest |
| February | 44°F (7°C) | 1.7 in | |
| March | 53°F (12°C) | 2.5 in | |
| April | 62°F (16°C) | 2.9 in | |
| May | 70°F (21°C) | 5.0 in | Wettest |
| June | 78°F (25°C) | 4.0 in | |
| July | 85°F (29°C) | 2.1 in | Warmest |
| August | 82°F (28°C) | 2.5 in | |
| September | 75°F (24°C) | 4.0 in | |
| October | 64°F (18°C) | 3.5 in | |
| November | 51°F (11°C) | 2.1 in | |
| December | 43°F (6°C) | 1.7 in | Coldest |
Duncan has a seasonal temperature swing of 42°F / from 43°F in December to 85°F in July. Total annual precipitation is 33.1 inches, with May being the wettest month (5.0") and January the driest (1.2").