Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Garden Prairie experiences four distinct seasons with an average annual temperature of 48°F (9°C). Winters average 21°F in January while summers reach 73°F in July. The area gets 260 sunny days per year, above the national average. Annual precipitation totals 37.6 inches. The area receives 30.8 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 780 feet.
Temperature
21°F Jan (-6°C)73°F Jul (23°C)
Annual Average
48.2°F
11% below US avg
January Average
21°F (-6°C)
July Average
73°F (23°C)
Sunny Days
260 days/yr
Geography
Elevation
780 ft (238 m)
Area
0.6 sq mi (1.7 km²)
Population Density
875/sq mi
Coordinates
42.2536°N, 88.7129°W
Timezone
America/Chicago
County
Boone County County
Nearest Airport
Chicago/Rockford International (RFD) 20 miles away
Precipitation & Snow
Annual Rainfall37.6"
1% below US avg
Snowfall30.8"
Wettest Month (Jun)4.29"
Driest Month (Feb)1.18"
Air Quality
AQI Median
43.0
Rating
Good
Natural Hazard Risk
Overall Risk
Relatively Low
Risk Score
57.4 / 100
Social Vulnerability
27.9 / 100
Community Resilience
72.2 / 100
Hazard Breakdown
Tornado
Relatively Moderate
Hurricane
Very Low
Earthquake
Very Low
Wildfire
Very Low
Flood
Relatively Low
Hail
Relatively Moderate
Strong Wind
Relatively Moderate
Heat Wave
Relatively Low
Winter Weather
Relatively Low
Lightning
Relatively Moderate
Ice Storm
Relatively Low
Drought
Relatively Low
Cold Wave
Relatively Moderate
Landslide
Very Low
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
8 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
90 km
10 km
Feb 10, 2010
2 km NW of Lily Lake, Illinois
M3.8
36 km
10 km
Sep 2, 1999
8 km W of Amboy, Illinois
M3.5
84 km
5 km
Nov 4, 2013
1 km SSW of Lyons, Illinois
M3.2
89 km
1 km
Jul 15, 2024
2 km WNW of Somonauk, Illinois
M3.1
68 km
10 km
Mar 25, 2015
3 km WNW of Lake in the Hills, Illinois
M2.9
30 km
6 km
Jun 10, 2013
4 km NNE of Virgil, Illinois
M2.6
34 km
5 km
Mar 15, 2025
6 km W of Dwight, Illinois
M2.6
131 km
5 km
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
634 tornadoes (EF0+) recorded within 100 km since 1950.
Strongest on record: EF5. Total: 114 fatalities, 2,231 injuries.
Date
Rating
Distance
Path
Fatalities
Aug 28, 1990
EF5
71 km
16.4 mi
29
Apr 9, 2015
EF4
65 km
30.1 mi
2
Apr 27, 1984
EF4
86 km
6.5 mi
1
Jun 29, 1979
EF4
91 km
5.4 mi
0
Jun 13, 1976
EF4
88 km
3.3 mi
2
Sep 28, 1972
EF4
69 km
5.2 mi
0
Apr 21, 1967
EF4
98 km
15.0 mi
33
Apr 21, 1967
EF4
18 km
25.5 mi
24
Apr 21, 1967
EF4
38 km
8.8 mi
1
Apr 11, 1965
EF4
28 km
9.1 mi
6
Jun 20, 2021
EF3
71 km
17.6 mi
0
Jan 7, 2008
EF3
18 km
13.2 mi
0
Jan 7, 2008
EF3
46 km
10.8 mi
0
Aug 18, 2005
EF3
95 km
18.6 mi
1
Jun 17, 1992
EF3
97 km
16.0 mi
0
Mar 27, 1991
EF3
91 km
15.0 mi
0
Apr 27, 1984
EF3
84 km
9.0 mi
1
Jun 5, 1980
EF3
98 km
10.7 mi
0
Aug 5, 1979
EF3
76 km
5.7 mi
0
Jun 30, 1977
EF3
79 km
6.1 mi
0
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Wildfire History
3 wildfires (100+ acres) recorded within 100 km.
Largest: IBSP SOUTH F1 RX (690 acres, 2024).
Year
Name
Acres Burned
Distance
2024
IBSP SOUTH F1 RX
690
76 km
2024
RX-HWY Y - SOUTH
553
79 km
2009
COLD SPRINGS
552
88 km
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
Month
Avg Temperature
Precipitation
Summary
January
21°F (-6°C)
1.4 in
Coldest
February
24°F (-4°C)
1.2 in
Driest
March
35°F (2°C)
2.4 in
April
47°F (9°C)
3.6 in
May
59°F (15°C)
3.7 in
June
69°F (20°C)
4.3 in
Wettest
July
73°F (23°C)
4.0 in
Warmest
August
70°F (21°C)
4.2 in
September
62°F (17°C)
3.8 in
October
51°F (11°C)
2.6 in
November
37°F (3°C)
2.7 in
December
25°F (-4°C)
2.0 in
Garden Prairie has a seasonal temperature swing of 52°F / from 21°F in January to 73°F in July. Total annual precipitation is 35.8 inches, with June being the wettest month (4.3") and February the driest (1.2").