Weather & Climate in Union Star, MO
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Union Star experiences four distinct seasons with an average annual temperature of 52°F (11°C). Winters average 26°F in January while summers reach 77°F in July. Annual precipitation totals 40.2 inches. The area receives 17.9 inches of snow annually, a moderate snowfall amount. The city sits at an elevation of 981 feet.
Temperature
26°F Jan (-4°C)
77°F Jul (25°C)
| Annual Average | 52.4°F |
| 3% below US avg | |
| January Average | 26°F (-4°C) |
| July Average | 77°F (25°C) |
Geography
| Elevation | 981 ft (299 m) |
| Area | 0.3 sq mi (0.7 km²) |
| Population Density | 1,962/sq mi |
| Coordinates | 39.9798°N, 94.5989°W |
| Timezone | America/Chicago |
| Nearest Airport | Kansas City International (MCI) 48 miles away |
Precipitation & Snow
Air Quality
Earthquake History
7 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M3.6.
| Dec 17, 2009 | 2 km NW of Auburn, Nebraska | M3.6 | 117 km | 5 km |
| Jul 16, 2004 | 6 km SSE of Riverton, Iowa | M3.5 | 109 km | 5 km |
| Mar 23, 2007 | 5 km N of Nortonville, Kansas | M3.1 | 86 km | 5 km |
| Feb 11, 1995 | 6 km E of Clearmont, Missouri | M3.1 | 66 km | 5 km |
| May 13, 1999 | 6 km WSW of Kansas City, Kansas | M3.0 | 98 km | 5 km |
| Mar 31, 1993 | 2 km SE of Nemaha, Nebraska | M2.9 | 97 km | 5 km |
| Jul 15, 2025 | 3 km W of Hale, Missouri | M2.5 | 112 km | 8 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Tornado History
518 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 13 fatalities, 341 injuries.
| Date | Rating | Distance | Path | Fatalities |
| May 29, 2004 | EF4 | 32 km | 22.0 mi | 3 |
| May 4, 2003 | EF4 | 84 km | 5.0 mi | 0 |
| Jun 7, 1984 | EF4 | 69 km | 134.0 mi | 3 |
| Jun 2, 1980 | EF4 | 92 km | 31.2 mi | 0 |
| Mar 29, 1979 | EF4 | 73 km | 18.8 mi | 0 |
| May 4, 1977 | EF4 | 90 km | 48.6 mi | 0 |
| May 4, 1977 | EF4 | 88 km | 12.0 mi | 0 |
| Apr 23, 1975 | EF4 | 62 km | 11.4 mi | 1 |
| Apr 21, 1973 | EF4 | 97 km | 14.6 mi | 0 |
| Apr 12, 1964 | EF4 | 94 km | 13.1 mi | 1 |
| May 7, 1961 | EF4 | 94 km | 26.2 mi | 0 |
| Apr 5, 1954 | EF4 | 92 km | 6.3 mi | 0 |
| May 2, 2008 | EF3 | 77 km | 0.9 mi | 0 |
| May 29, 2004 | EF3 | 55 km | 7.0 mi | 0 |
| Apr 11, 2001 | EF3 | 49 km | 76.5 mi | 0 |
| May 27, 1995 | EF3 | 83 km | 30.4 mi | 0 |
| Jun 7, 1984 | EF3 | 91 km | 25.0 mi | 0 |
| Apr 26, 1984 | EF3 | 96 km | 32.0 mi | 0 |
| Mar 29, 1979 | EF3 | 90 km | 57.0 mi | 0 |
| Mar 29, 1979 | EF3 | 73 km | 29.6 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Wildfire History
7 wildfires (100+ acres) recorded within 100 km. Largest: MOSQR-FY20-RX-WUI (964 acres, 2020).
| Year | Name | Acres Burned | Distance |
| 2020 | MOSQR-FY20-RX-WUI | 964 | 58 km |
| 2012 | HIGHWAY E | 897 | 80 km |
| 2016 | SQR BM SL DESOTO 2016 WUI RX | 866 | 58 km |
| 1988 | NORTH POOL | 698 | 58 km |
| 2020 | UNNAMED | 645 | 57 km |
| 2009 | UNIT 6 | 625 | 57 km |
| 2002 | SCRDGRS 6 | 536 | 57 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 26°F (-4°C) | 1.0 in | Coldest, Driest |
| February | 30°F (-1°C) | 1.4 in | |
| March | 41°F (5°C) | 2.3 in | |
| April | 52°F (11°C) | 3.8 in | |
| May | 63°F (17°C) | 5.6 in | |
| June | 73°F (23°C) | 5.9 in | Wettest |
| July | 77°F (25°C) | 5.0 in | Warmest |
| August | 75°F (24°C) | 4.3 in | |
| September | 67°F (19°C) | 4.3 in | |
| October | 54°F (12°C) | 3.3 in | |
| November | 41°F (5°C) | 2.0 in | |
| December | 30°F (-1°C) | 1.4 in |
Union Star has a seasonal temperature swing of 51°F / from 26°F in January to 77°F in July. Total annual precipitation is 40.2 inches, with June being the wettest month (5.9") and January the driest (1.0").