All Countries
Weather & Climate in Unionville, IA
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Unionville experiences four distinct seasons with an average annual temperature of 50°F (10°C). Winters average 22°F in January while summers reach 75°F in July. The area gets 275 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 38.6 inches. Air quality is rated Good with a median AQI of 43. The city sits at an elevation of 949 feet.
Temperature
22°F Jan (-6°C)
75°F Jul (24°C)
| Annual Average | 50.4°F |
| 7% below US avg | |
| January Average | 22°F (-6°C) |
| July Average | 75°F (24°C) |
| Sunny Days | 275 days/yr |
Geography
| Elevation | 949 ft (289 m) |
| Area | 0.7 sq mi (1.9 km²) |
| Population Density | 115/sq mi |
| Coordinates | 40.8181°N, 92.6958°W |
| Timezone | America/Chicago |
| County | Appanoose County County |
| Nearest Airport | Ottumwa Regional (OTM) 24 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 43.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Very Low |
| Risk Score | 41.2 / 100 |
| Social Vulnerability | 70.0 / 100 |
| Community Resilience | 60.0 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Hurricane | Very Low |
| Earthquake | Very Low |
| Wildfire | Very Low |
| Flood | Very Low |
| Hail | Relatively Low |
| Strong Wind | Relatively Moderate |
| Heat Wave | Relatively Low |
| Winter Weather | Very Low |
| Lightning | Relatively Low |
| Ice Storm | Relatively Low |
| Drought | Relatively High |
| Cold Wave | Relatively Low |
| Landslide | Relatively Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
1 earthquake (M2.5+) recorded within 150 km since 1990. Strongest on record: M2.5.
| Jul 15, 2025 | 3 km W of Hale, Missouri | M2.5 | 148 km | 8 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
420 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 12 fatalities, 200 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Mar 31, 2023 | EF4 | 78 km | 19.9 mi | 0 |
| Apr 21, 1973 | EF4 | 90 km | 14.6 mi | 0 |
| Jan 24, 1967 | EF4 | 49 km | 25.7 mi | 0 |
| May 20, 1959 | EF4 | 40 km | 17.2 mi | 0 |
| May 10, 1953 | EF4 | 54 km | 6.4 mi | 0 |
| Mar 31, 2023 | EF3 | 41 km | 26.1 mi | 0 |
| Mar 5, 2022 | EF3 | 60 km | 11.3 mi | 1 |
| Aug 20, 2019 | EF3 | 85 km | 5.4 mi | 0 |
| May 27, 2019 | EF3 | 61 km | 7.3 mi | 0 |
| Jul 19, 2018 | EF3 | 74 km | 9.2 mi | 0 |
| Jun 22, 2015 | EF3 | 52 km | 11.1 mi | 0 |
| Apr 8, 1999 | EF3 | 75 km | 39.0 mi | 0 |
| Apr 8, 1999 | EF3 | 24 km | 16.0 mi | 0 |
| May 15, 1998 | EF3 | 96 km | 47.0 mi | 0 |
| May 1, 1973 | EF3 | 93 km | 3.6 mi | 2 |
| Apr 20, 1973 | EF3 | 70 km | 9.5 mi | 0 |
| Apr 21, 1967 | EF3 | 68 km | 0.1 mi | 0 |
| Apr 16, 1967 | EF3 | 52 km | 19.4 mi | 2 |
| Jan 24, 1967 | EF3 | 52 km | 25.0 mi | 0 |
| Oct 14, 1966 | EF3 | 86 km | 29.5 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Wildfire History
1 wildfire (100+ acres) recorded within 100 km. Largest: NEAL SMITH WUI 2016 1 (1,050 acres, 2016).
| Year | Name | Acres Burned | Distance |
| 2016 | NEAL SMITH WUI 2016 1 | 1,050 | 98 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 22°F (-6°C) | 1.1 in | Coldest |
| February | 28°F (-2°C) | 1.0 in | Driest |
| March | 39°F (4°C) | 2.5 in | |
| April | 51°F (11°C) | 3.4 in | |
| May | 62°F (17°C) | 4.3 in | |
| June | 71°F (22°C) | 4.3 in | |
| July | 75°F (24°C) | 4.6 in | Warmest, Wettest |
| August | 74°F (23°C) | 4.1 in | |
| September | 65°F (18°C) | 4.3 in | |
| October | 54°F (12°C) | 3.0 in | |
| November | 40°F (4°C) | 2.2 in | |
| December | 27°F (-3°C) | 1.5 in |
Unionville has a seasonal temperature swing of 53°F / from 22°F in January to 75°F in July. Total annual precipitation is 36.2 inches, with July being the wettest month (4.6") and February the driest (1.0").