Weather & Climate in Long Grove, IA
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Long Grove experiences four distinct seasons with an average annual temperature of 50°F (10°C). Winters average 22°F in January while summers reach 74°F in July. Annual precipitation totals 36.2 inches. The area receives 28.7 inches of snow annually, a moderate snowfall amount. Air quality is rated Good with a median AQI of 46. 61% of days have good air quality. The city sits at an elevation of 798 feet.
Temperature
22°F Jan (-6°C)
74°F Jul (23°C)
| Annual Average | 49.9°F |
| 8% below US avg | |
| January Average | 22°F (-6°C) |
| July Average | 74°F (23°C) |
Geography
| Elevation | 798 ft (243 m) |
| Area | 1.2 sq mi (3.0 km²) |
| Population Density | 615/sq mi |
| Coordinates | 41.6922°N, 90.5803°W |
| Timezone | America/Chicago |
| County | Scott County County |
| Nearest Airport | Quad Cities International (MLI) 17 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 46.0 |
| Rating | Good |
| Good Days % | 61.2% |
| Unhealthy Days | 0 |
Natural Hazard Risk
| Overall Risk | Relatively Moderate |
| Risk Score | 84.9 / 100 |
| Social Vulnerability | 19.2 / 100 |
| Community Resilience | 95.9 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Hurricane | Very Low |
| Earthquake | Relatively Low |
| Wildfire | Very Low |
| Flood | Relatively Moderate |
| Hail | Relatively High |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Moderate |
| Winter Weather | Relatively High |
| Lightning | Relatively High |
| Ice Storm | Relatively High |
| Drought | Relatively Moderate |
| Cold Wave | Relatively Moderate |
| Landslide | Relatively Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
2 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 | 142 km | 10 km |
| Sep 2, 1999 | 8 km W of Amboy, Illinois | M3.5 | 95 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Tornado History
639 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 7 fatalities, 192 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Mar 13, 1990 | EF4 | 92 km | 19.0 mi | 0 |
| Mar 29, 1981 | EF4 | 52 km | 5.1 mi | 0 |
| Apr 11, 1965 | EF4 | 34 km | 91.5 mi | 1 |
| Jun 1, 2007 | EF3 | 69 km | 15.8 mi | 0 |
| May 9, 1995 | EF3 | 27 km | 10.0 mi | 0 |
| May 9, 1995 | EF3 | 78 km | 22.0 mi | 0 |
| Jun 19, 1993 | EF3 | 71 km | 14.0 mi | 0 |
| Jul 13, 1992 | EF3 | 71 km | 5.0 mi | 0 |
| Mar 13, 1990 | EF3 | 27 km | 15.5 mi | 0 |
| May 8, 1988 | EF3 | 18 km | 32.0 mi | 0 |
| Aug 5, 1979 | EF3 | 91 km | 5.7 mi | 0 |
| Aug 15, 1978 | EF3 | 50 km | 6.4 mi | 0 |
| Jun 20, 1974 | EF3 | 41 km | 10.6 mi | 1 |
| Jun 14, 1974 | EF3 | 36 km | 48.6 mi | 0 |
| May 13, 1974 | EF3 | 8 km | 3.6 mi | 0 |
| Sep 9, 1970 | EF3 | 90 km | 4.7 mi | 0 |
| Jan 24, 1967 | EF3 | 61 km | 7.4 mi | 0 |
| Apr 19, 1966 | EF3 | 22 km | 2.0 mi | 0 |
| May 7, 1962 | EF3 | 12 km | 10.0 mi | 0 |
| May 20, 1953 | EF3 | 88 km | 38.6 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Wildfire History
5 wildfires (100+ acres) recorded within 100 km. Largest: UNIT 3 (1,206 acres, 1999).
| Year | Name | Acres Burned | Distance |
| 1999 | UNIT 3 | 1,206 | 77 km |
| 2002 | HSB 03 2 | 1,130 | 77 km |
| 2000 | DESTRUST A | 756 | 77 km |
| 2006 | HSB 003 | 674 | 78 km |
| 2004 | HSB 009 | 608 | 77 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 22°F (-6°C) | 1.1 in | Coldest, Driest |
| February | 26°F (-3°C) | 1.4 in | |
| March | 39°F (4°C) | 2.3 in | |
| April | 50°F (10°C) | 3.6 in | |
| May | 62°F (17°C) | 4.8 in | Wettest |
| June | 71°F (22°C) | 4.7 in | |
| July | 74°F (23°C) | 4.1 in | Warmest |
| August | 72°F (22°C) | 4.0 in | |
| September | 65°F (18°C) | 3.5 in | |
| October | 53°F (11°C) | 2.7 in | |
| November | 39°F (4°C) | 2.3 in | |
| December | 28°F (-2°C) | 1.6 in |
Long Grove has a seasonal temperature swing of 52°F / from 22°F in January to 74°F in July. Total annual precipitation is 36.2 inches, with May being the wettest month (4.8") and January the driest (1.1").