Weather & Climate in Mount Union, IA
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Mount Union experiences four distinct seasons with an average annual temperature of 50°F (10°C). Winters average 22°F in January while summers reach 74°F in July. Annual precipitation totals 38.4 inches. The area receives 24.8 inches of snow annually, a moderate snowfall amount. The city sits at an elevation of 733 feet.
Temperature
22°F Jan (-6°C)
74°F Jul (23°C)
| Annual Average | 49.7°F |
| 8% below US avg | |
| January Average | 22°F (-6°C) |
| July Average | 74°F (23°C) |
Geography
| Elevation | 733 ft (223 m) |
| Area | 0.1 sq mi (0.3 km²) |
| Population Density | 653/sq mi |
| Coordinates | 41.0577°N, 91.3914°W |
| Timezone | America/Chicago |
| County | Louisa County County |
| Nearest Airport | Southeast Iowa Regional (BRL) 24 miles away |
Precipitation & Snow
Air Quality
Natural Hazard Risk
| Overall Risk | Very Low |
| Risk Score | 17.5 / 100 |
| Social Vulnerability | 13.6 / 100 |
| Community Resilience | 58.2 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| 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 Moderate |
| Cold Wave | Very Low |
| Landslide | Relatively Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Tornado History
574 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 14 fatalities, 269 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Mar 31, 2023 | EF4 | 60 km | 19.9 mi | 0 |
| May 13, 1995 | EF4 | 54 km | 50.0 mi | 0 |
| Apr 11, 1965 | EF4 | 96 km | 91.5 mi | 1 |
| Mar 31, 2023 | EF3 | 79 km | 26.1 mi | 0 |
| May 27, 2019 | EF3 | 67 km | 7.3 mi | 0 |
| Jun 1, 2007 | EF3 | 29 km | 15.8 mi | 0 |
| Apr 8, 1999 | EF3 | 79 km | 7.5 mi | 0 |
| Apr 8, 1999 | EF3 | 93 km | 16.0 mi | 0 |
| May 15, 1998 | EF3 | 38 km | 47.0 mi | 0 |
| May 9, 1995 | EF3 | 73 km | 10.0 mi | 0 |
| May 8, 1988 | EF3 | 92 km | 32.0 mi | 0 |
| Aug 15, 1978 | EF3 | 56 km | 6.4 mi | 0 |
| Jun 14, 1974 | EF3 | 70 km | 48.6 mi | 0 |
| May 13, 1974 | EF3 | 91 km | 3.6 mi | 0 |
| Apr 13, 1974 | EF3 | 88 km | 11.0 mi | 0 |
| Sep 30, 1973 | EF3 | 100 km | 0.1 mi | 0 |
| May 1, 1973 | EF3 | 76 km | 3.6 mi | 2 |
| Apr 20, 1973 | EF3 | 89 km | 9.5 mi | 0 |
| Apr 21, 1967 | EF3 | 46 km | 0.1 mi | 0 |
| Apr 16, 1967 | EF3 | 72 km | 19.4 mi | 2 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Wildfire History
5 wildfires (100+ acres) recorded within 100 km. Largest: UNIT 3 (1,206 acres, 1999).
| Year | Name | Acres Burned | Distance |
| 1999 | UNIT 3 | 1,206 | 26 km |
| 2002 | HSB 03 2 | 1,130 | 25 km |
| 2000 | DESTRUST A | 756 | 26 km |
| 2006 | HSB 003 | 674 | 26 km |
| 2004 | HSB 009 | 608 | 26 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 22°F (-6°C) | 1.4 in | Coldest, Driest |
| February | 27°F (-3°C) | 1.7 in | |
| March | 38°F (3°C) | 2.3 in | |
| April | 50°F (10°C) | 3.9 in | |
| May | 61°F (16°C) | 5.1 in | |
| June | 70°F (21°C) | 5.1 in | Wettest |
| July | 74°F (23°C) | 4.4 in | Warmest |
| August | 72°F (22°C) | 3.9 in | |
| September | 65°F (18°C) | 4.1 in | |
| October | 52°F (11°C) | 2.9 in | |
| November | 39°F (4°C) | 2.1 in | |
| December | 28°F (-3°C) | 1.7 in |
Mount Union has a seasonal temperature swing of 52°F / from 22°F in January to 74°F in July. Total annual precipitation is 38.5 inches, with June being the wettest month (5.1") and January the driest (1.4").