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Weather & Climate in Eureka, IL
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Eureka experiences four distinct seasons with an average annual temperature of 52°F (11°C). Winters average 25°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 37.5 inches. The area receives 22.3 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 740 feet.
Temperature
25°F Jan (-4°C)
75°F Jul (24°C)
| Annual Average | 52.1°F |
| 4% below US avg | |
| January Average | 25°F (-4°C) |
| July Average | 75°F (24°C) |
| Sunny Days | 275 days/yr |
Geography
| Elevation | 740 ft (226 m) |
| Area | 2.7 sq mi (7.1 km²) |
| Population Density | 1,859/sq mi |
| Coordinates | 40.7140°N, 89.2770°W |
| Timezone | America/Chicago |
| County | Woodford County County |
| Nearest Airport | General Downing - Peoria International (PIA) 22 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 43.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Very Low |
| Risk Score | 39.9 / 100 |
| Social Vulnerability | 10.6 / 100 |
| Community Resilience | 96.1 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Hurricane | Very Low |
| Earthquake | Very Low |
| Wildfire | Very Low |
| Flood | Relatively Low |
| Hail | Very Low |
| Strong Wind | Relatively Low |
| Heat Wave | Relatively Low |
| Winter Weather | Relatively Low |
| Lightning | Very Low |
| Ice Storm | Relatively Low |
| Drought | Relatively Moderate |
| Cold Wave | Relatively Moderate |
| 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: M4.2.
| Jun 28, 2004 | 12 km NW of Dayton, Illinois | M4.2 | 89 km | 10 km |
| Sep 2, 1999 | 8 km W of Amboy, Illinois | M3.5 | 113 km | 5 km |
| Jul 15, 2024 | 2 km WNW of Somonauk, Illinois | M3.1 | 114 km | 10 km |
| Mar 15, 2025 | 6 km W of Dwight, Illinois | M2.6 | 77 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
714 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 24 fatalities, 678 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Nov 17, 2013 | EF4 | 27 km | 46.4 mi | 3 |
| Jul 13, 2004 | EF4 | 11 km | 9.6 mi | 0 |
| May 13, 1995 | EF4 | 95 km | 7.0 mi | 0 |
| May 5, 1977 | EF4 | 52 km | 7.3 mi | 0 |
| Jun 29, 1976 | EF4 | 41 km | 4.9 mi | 0 |
| Apr 4, 2023 | EF3 | 98 km | 19.9 mi | 0 |
| Feb 28, 2017 | EF3 | 23 km | 17.8 mi | 0 |
| Feb 28, 2017 | EF3 | 73 km | 11.5 mi | 2 |
| Jun 22, 2015 | EF3 | 100 km | 16.3 mi | 0 |
| Dec 31, 2010 | EF3 | 95 km | 3.6 mi | 0 |
| Jun 5, 2010 | EF3 | 63 km | 8.6 mi | 0 |
| Aug 19, 2009 | EF3 | 88 km | 24.3 mi | 0 |
| Apr 20, 2004 | EF3 | 60 km | 15.8 mi | 8 |
| May 10, 2003 | EF3 | 44 km | 17.5 mi | 0 |
| Apr 19, 1996 | EF3 | 44 km | 9.4 mi | 0 |
| Apr 19, 1996 | EF3 | 100 km | 14.5 mi | 0 |
| May 13, 1995 | EF3 | 64 km | 25.0 mi | 0 |
| May 9, 1995 | EF3 | 79 km | 22.0 mi | 0 |
| Jun 30, 1977 | EF3 | 99 km | 6.1 mi | 0 |
| Mar 4, 1976 | EF3 | 59 km | 0.8 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 25°F (-4°C) | 1.6 in | Coldest |
| February | 27°F (-3°C) | 1.6 in | Driest |
| March | 39°F (4°C) | 3.0 in | |
| April | 51°F (10°C) | 3.8 in | |
| May | 62°F (17°C) | 4.1 in | Wettest |
| June | 71°F (22°C) | 4.0 in | |
| July | 75°F (24°C) | 3.9 in | Warmest |
| August | 72°F (22°C) | 3.4 in | |
| September | 65°F (18°C) | 3.8 in | |
| October | 53°F (12°C) | 2.8 in | |
| November | 40°F (4°C) | 3.0 in | |
| December | 28°F (-2°C) | 2.6 in |
Eureka has a seasonal temperature swing of 50°F / from 25°F in January to 75°F in July. Total annual precipitation is 37.6 inches, with May being the wettest month (4.1") and February the driest (1.6").