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Weather & Climate in Onawa, IA
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Onawa experiences four distinct seasons with an average annual temperature of 49°F (9°C). Winters average 19°F in January while summers reach 74°F in July. The area gets 291 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 29.9 inches (drier than the 38-inch national average). The area receives 31.0 inches of snow annually, a moderate snowfall amount. Air quality is rated Good with a median AQI of 43. The city sits at an elevation of 1,049 feet.
Temperature
19°F Jan (-7°C)
74°F Jul (24°C)
| Annual Average | 48.5°F |
| 10% below US avg | |
| January Average | 19°F (-7°C) |
| July Average | 74°F (24°C) |
| Sunny Days | 291 days/yr |
Geography
| Elevation | 1,049 ft (320 m) |
| Area | 5.2 sq mi (13.4 km²) |
| Population Density | 543/sq mi |
| Coordinates | 42.0265°N, 96.0909°W |
| Timezone | America/Chicago |
| County | Thurston County County |
| Nearest Airport | Sioux Gateway/Brig General Bud Day Field (SUX) 30 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 43.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Very Low |
| Risk Score | 26.4 / 100 |
| Social Vulnerability | 69.5 / 100 |
| Community Resilience | 20.7 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Earthquake | Very Low |
| Wildfire | Relatively Low |
| Flood | Very Low |
| Hail | Relatively Moderate |
| Strong Wind | Relatively Low |
| Heat Wave | Relatively Low |
| Winter Weather | Very Low |
| Lightning | Very Low |
| Ice Storm | Relatively Low |
| Drought | Relatively Moderate |
| Cold Wave | Relatively Low |
| Landslide | Relatively Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
4 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M3.6.
| Feb 6, 1996 | 1 km N of Wausa, Nebraska | M3.6 | 131 km | 5 km |
| Aug 9, 1997 | 9 km NW of Clarkson, Nebraska | M3.4 | 94 km | 5 km |
| Feb 5, 2025 | 8 km SSE of Tilden, Nebraska | M2.7 | 142 km | 5 km |
| Jun 30, 2021 | 4 km E of Rembrandt, Iowa | M2.7 | 120 km | 10 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
572 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 15 fatalities, 515 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Apr 26, 2024 | EF4 | 94 km | 31.9 mi | 0 |
| Jun 16, 2014 | EF4 | 65 km | 15.8 mi | 0 |
| Jun 16, 2014 | EF4 | 87 km | 23.9 mi | 1 |
| Jun 16, 2014 | EF4 | 79 km | 11.5 mi | 1 |
| Oct 4, 2013 | EF4 | 34 km | 24.7 mi | 0 |
| Oct 4, 2013 | EF4 | 82 km | 18.3 mi | 0 |
| May 27, 1995 | EF4 | 99 km | 36.0 mi | 0 |
| Jul 7, 1977 | EF4 | 52 km | 22.6 mi | 0 |
| Jun 26, 1976 | EF4 | 76 km | 5.1 mi | 0 |
| May 6, 1975 | EF4 | 95 km | 8.0 mi | 3 |
| Aug 13, 1952 | EF4 | 99 km | 26.7 mi | 0 |
| Jun 23, 1952 | EF4 | 83 km | 24.1 mi | 0 |
| Jul 15, 1950 | EF4 | 49 km | 10.0 mi | 0 |
| Apr 26, 2024 | EF3 | 99 km | 13.3 mi | 0 |
| Apr 26, 2024 | EF3 | 88 km | 40.3 mi | 1 |
| Apr 26, 2024 | EF3 | 87 km | 19.1 mi | 0 |
| Apr 9, 2011 | EF3 | 26 km | 3.4 mi | 0 |
| Apr 9, 2011 | EF3 | 76 km | 10.1 mi | 0 |
| Apr 9, 2011 | EF3 | 96 km | 29.4 mi | 0 |
| Jun 11, 2008 | EF3 | 25 km | 14.2 mi | 4 |
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Wildfire History
1 wildfire (100+ acres) recorded within 100 km. Largest: UNNAMED (629 acres, 2010).
| Year | Name | Acres Burned | Distance |
| 2010 | UNNAMED | 629 | 72 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 19°F (-7°C) | 0.6 in | Coldest, Driest |
| February | 26°F (-3°C) | 0.7 in | |
| March | 38°F (3°C) | 2.1 in | |
| April | 51°F (10°C) | 2.8 in | |
| May | 62°F (17°C) | 4.1 in | |
| June | 72°F (22°C) | 4.3 in | Wettest |
| July | 74°F (24°C) | 3.4 in | Warmest |
| August | 73°F (23°C) | 3.3 in | |
| September | 64°F (18°C) | 3.2 in | |
| October | 52°F (11°C) | 2.2 in | |
| November | 36°F (2°C) | 1.2 in | |
| December | 24°F (-5°C) | 0.8 in |
Onawa has a seasonal temperature swing of 55°F / from 19°F in January to 74°F in July. Total annual precipitation is 28.7 inches, with June being the wettest month (4.3") and January the driest (0.6").