All Countries
Weather & Climate in Dewey, IL
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Dewey experiences four distinct seasons with an average annual temperature of 52°F (11°C). Winters average 25°F in January while summers reach 76°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 40.4 inches. Air quality is rated Good with a median AQI of 43. The city sits at an elevation of 731 feet.
Temperature
25°F Jan (-4°C)
76°F Jul (24°C)
| Annual Average | 52.3°F |
| 3% below US avg | |
| January Average | 25°F (-4°C) |
| July Average | 76°F (24°C) |
| Sunny Days | 275 days/yr |
Geography
| Elevation | 731 ft (223 m) |
| Area | 0.1 sq mi (0.3 km²) |
| Population Density | 710/sq mi |
| Coordinates | 40.3193°N, 88.2834°W |
| Timezone | America/Chicago |
| County | Champaign County County |
| Nearest Airport | Central Il Regional/Bloomington-Normal (BMI) 35 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 43.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively Moderate |
| Risk Score | 90.5 / 100 |
| Social Vulnerability | 30.9 / 100 |
| Community Resilience | 86.3 / 100 |
Hazard Breakdown
| Tornado | Relatively High |
| Hurricane | Very Low |
| Earthquake | Relatively Low |
| Wildfire | Very Low |
| Flood | Relatively Moderate |
| Hail | Relatively Moderate |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Moderate |
| Winter Weather | Relatively High |
| Lightning | Relatively Moderate |
| Ice Storm | Relatively Moderate |
| Drought | Relatively High |
| Cold Wave | Relatively High |
| Landslide | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
7 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 | 137 km | 10 km |
| Jun 17, 2021 | Illinois-Indiana border region | M3.8 | 101 km | 6 km |
| Apr 14, 2000 | 4 km NW of Heritage Lake, Indiana | M3.6 | 145 km | 5 km |
| May 13, 2025 | 7 km SSW of Lerna, Illinois | M3.3 | 107 km | 10 km |
| Dec 17, 1990 | Illinois-Indiana border region | M3.2 | 109 km | 10 km |
| Dec 16, 1996 | 3 km NNE of Terre Haute, Indiana | M3.1 | 118 km | 5 km |
| Mar 15, 2025 | 6 km W of Dwight, Illinois | M2.6 | 87 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
744 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 33 fatalities, 834 injuries.
| Date | Rating | Distance | Path | Fatalities |
| May 5, 1977 | EF4 | 82 km | 7.3 mi | 0 |
| Mar 20, 1976 | EF4 | 73 km | 63.7 mi | 0 |
| Apr 3, 1974 | EF4 | 100 km | 108.7 mi | 18 |
| Apr 17, 1963 | EF4 | 97 km | 57.3 mi | 1 |
| Nov 17, 2013 | EF3 | 14 km | 29.8 mi | 0 |
| Nov 17, 2013 | EF3 | 53 km | 18.7 mi | 0 |
| Jun 5, 2010 | EF3 | 94 km | 7.8 mi | 0 |
| Jun 5, 2010 | EF3 | 95 km | 8.6 mi | 0 |
| Apr 19, 1996 | EF3 | 36 km | 2.0 mi | 1 |
| Apr 19, 1996 | EF3 | 28 km | 4.0 mi | 0 |
| Apr 19, 1996 | EF3 | 90 km | 9.4 mi | 0 |
| Apr 19, 1996 | EF3 | 94 km | 14.5 mi | 0 |
| Apr 2, 1982 | EF3 | 85 km | 12.0 mi | 0 |
| Mar 12, 1976 | EF3 | 90 km | 38.5 mi | 1 |
| Aug 10, 1974 | EF3 | 86 km | 0.1 mi | 0 |
| Apr 3, 1974 | EF3 | 98 km | 20.9 mi | 1 |
| Apr 3, 1974 | EF3 | 38 km | 5.9 mi | 1 |
| Apr 3, 1974 | EF3 | 68 km | 25.9 mi | 0 |
| Apr 3, 1974 | EF3 | 36 km | 7.4 mi | 0 |
| Apr 3, 1974 | EF3 | 45 km | 14.9 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Wildfire History
1 wildfire (100+ acres) recorded within 100 km. Largest: UNNAMED (1,602 acres, 2000).
| Year | Name | Acres Burned | Distance |
| 2000 | UNNAMED | 1,602 | 96 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 25°F (-4°C) | 1.8 in | Coldest |
| February | 28°F (-2°C) | 1.7 in | Driest |
| March | 40°F (4°C) | 3.1 in | |
| April | 51°F (11°C) | 3.7 in | |
| May | 62°F (17°C) | 4.2 in | |
| June | 71°F (22°C) | 3.9 in | |
| July | 76°F (24°C) | 4.3 in | Warmest, Wettest |
| August | 72°F (22°C) | 3.9 in | |
| September | 66°F (19°C) | 3.3 in | |
| October | 54°F (12°C) | 2.7 in | |
| November | 41°F (5°C) | 3.1 in | |
| December | 30°F (-1°C) | 2.8 in |
Dewey has a seasonal temperature swing of 51°F / from 25°F in January to 76°F in July. Total annual precipitation is 38.5 inches, with July being the wettest month (4.3") and February the driest (1.7").