Weather & Climate in Decker, IN
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Decker experiences four distinct seasons with an average annual temperature of 55°F (13°C). Winters average 30°F in January while summers reach 77°F in July. Annual precipitation totals 47.6 inches (wetter than the 38-inch national average). The area receives 12.2 inches of snow annually. Air quality is rated Good with a median AQI of 38. 87% of days have good air quality. The city sits at an elevation of 453 feet.
Temperature
30°F Jan (-1°C)
77°F Jul (25°C)
| Annual Average | 55.0°F |
| 2% above US avg | |
| January Average | 30°F (-1°C) |
| July Average | 77°F (25°C) |
Geography
| Elevation | 453 ft (138 m) |
| Area | 0.2 sq mi (0.5 km²) |
| Population Density | 1,074/sq mi |
| Coordinates | 38.5185°N, 87.5241°W |
| Timezone | America/Indiana/Indianapolis |
| County | Knox County County |
| Nearest Airport | Lawrenceville-Vincennes International (LWV) 18 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 38.0 |
| Rating | Good |
| Good Days % | 87.2% |
| Unhealthy Days | 0 |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 55.3 / 100 |
| Social Vulnerability | 37.2 / 100 |
| Community Resilience | 84.4 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Hurricane | Very Low |
| Earthquake | Relatively Moderate |
| Wildfire | Very Low |
| Flood | Relatively Low |
| Hail | Relatively Low |
| Strong Wind | Relatively Moderate |
| Heat Wave | Relatively Low |
| Winter Weather | Relatively Moderate |
| Lightning | Relatively Moderate |
| 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
68 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M5.2.
| Apr 18, 2008 | 7 km NNE of Bellmont, Illinois | M5.2 | 32 km | 14 km |
| Apr 18, 2008 | 9 km NNE of Bellmont, Illinois | M4.7 | 31 km | 15 km |
| Jun 18, 2002 | 6 km SW of Parkers Settlement, Indiana | M4.6 | 61 km | 16 km |
| Apr 21, 2008 | 7 km NNE of Bellmont, Illinois | M4.0 | 32 km | 18 km |
| Jan 24, 1990 | 6 km WNW of Alton, Indiana | M3.9 | 100 km | 10 km |
| Dec 7, 2000 | 7 km W of Evansville, Indiana | M3.9 | 62 km | 5 km |
| Jun 17, 2021 | Illinois-Indiana border region | M3.8 | 147 km | 6 km |
| Sep 19, 2017 | 4 km N of Bellmont, Illinois | M3.8 | 35 km | 12 km |
| Jan 27, 1990 | 6 km N of Alton, Indiana | M3.8 | 102 km | 5 km |
| Nov 11, 1991 | 3 km W of Flat Rock, Illinois | M3.8 | 46 km | 0 km |
| Apr 25, 2008 | 8 km NNE of Bellmont, Illinois | M3.7 | 31 km | 13 km |
| Dec 20, 1990 | 5 km S of Stilesville, Indiana | M3.7 | 142 km | 5 km |
| Jan 2, 2006 | 3 km NNE of Eldorado, Illinois | M3.6 | 108 km | 7 km |
| Nov 20, 2012 | 7 km N of Bellmont, Illinois | M3.6 | 34 km | 19 km |
| May 30, 2015 | 4 km ENE of Geff, Illinois | M3.4 | 73 km | 26 km |
| Jun 5, 2008 | 8 km WNW of Mount Carmel, Illinois | M3.4 | 29 km | 16 km |
| Mar 2, 1990 | 9 km NW of Vernon, Illinois | M3.4 | 148 km | 0 km |
| May 1, 2008 | 8 km NNE of Bellmont, Illinois | M3.3 | 30 km | 14 km |
| May 13, 2025 | 7 km SSW of Lerna, Illinois | M3.3 | 116 km | 10 km |
| Jan 29, 1993 | 7 km WNW of Brownstown, Illinois | M3.2 | 143 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Tornado History
483 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF5. Total: 50 fatalities, 753 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Apr 3, 1974 | EF5 | 84 km | 68.0 mi | 6 |
| Jun 2, 1990 | EF4 | 83 km | 23.0 mi | 0 |
| Jun 2, 1990 | EF4 | 7 km | 13.0 mi | 6 |
| Jun 2, 1990 | EF4 | 88 km | 106.0 mi | 1 |
| Jun 2, 1990 | EF4 | 91 km | 11.0 mi | 1 |
| Jun 2, 1990 | EF4 | 81 km | 12.5 mi | 0 |
| Jan 7, 1989 | EF4 | 23 km | 19.0 mi | 0 |
| Jul 9, 2024 | EF3 | 72 km | 5.8 mi | 0 |
| Mar 31, 2023 | EF3 | 63 km | 40.9 mi | 6 |
| Feb 28, 2017 | EF3 | 67 km | 44.1 mi | 1 |
| Nov 17, 2013 | EF3 | 98 km | 14.1 mi | 0 |
| Mar 8, 2009 | EF3 | 88 km | 1.1 mi | 0 |
| Oct 18, 2007 | EF3 | 89 km | 7.0 mi | 0 |
| Nov 15, 2005 | EF3 | 39 km | 12.0 mi | 0 |
| Nov 6, 2005 | EF3 | 80 km | 41.3 mi | 24 |
| May 30, 2004 | EF3 | 86 km | 15.0 mi | 1 |
| Jan 3, 2000 | EF3 | 94 km | 7.0 mi | 0 |
| Jun 2, 1990 | EF3 | 44 km | 7.0 mi | 0 |
| Apr 3, 1989 | EF3 | 31 km | 3.1 mi | 0 |
| Aug 10, 1974 | EF3 | 95 km | 0.1 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Wildfire History
6 wildfires (100+ acres) recorded within 100 km. Largest: UNNAMED (1,336 acres, 2017).
| Year | Name | Acres Burned | Distance |
| 2017 | UNNAMED | 1,336 | 99 km |
| 2021 | UNNAMED | 959 | 100 km |
| 2024 | LONG RUN RX | 774 | 96 km |
| 2010 | RICEVILLE RX | 671 | 79 km |
| 2019 | UNNAMED | 584 | 96 km |
| 2010 | ROCKHOUSE HOLLOW RX | 581 | 97 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 30°F (-1°C) | 3.5 in | Coldest |
| February | 34°F (1°C) | 2.7 in | Driest |
| March | 44°F (7°C) | 3.8 in | |
| April | 55°F (13°C) | 4.9 in | |
| May | 65°F (18°C) | 5.4 in | Wettest |
| June | 74°F (23°C) | 4.7 in | |
| July | 77°F (25°C) | 4.4 in | Warmest |
| August | 76°F (24°C) | 3.4 in | |
| September | 69°F (20°C) | 3.6 in | |
| October | 57°F (14°C) | 3.6 in | |
| November | 44°F (7°C) | 4.0 in | |
| December | 35°F (2°C) | 3.6 in |
Decker has a seasonal temperature swing of 47°F / from 30°F in January to 77°F in July. Total annual precipitation is 47.6 inches, with May being the wettest month (5.4") and February the driest (2.7").