Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Fox River Grove experiences four distinct seasons with an average annual temperature of 48°F (9°C). Winters average 21°F in January while summers reach 72°F in July. The area gets 246 sunny days per year, above the national average. Annual precipitation totals 40.4 inches. The area receives 38.5 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 769 feet.
Temperature
21°F Jan (-6°C)72°F Jul (22°C)
Annual Average
48.0°F
11% below US avg
January Average
21°F (-6°C)
July Average
72°F (22°C)
Sunny Days
246 days/yr
Geography
Elevation
769 ft (234 m)
Area
0.7 sq mi (1.7 km²)
Population Density
2,632/sq mi
Coordinates
42.1955°N, 88.2148°W
Timezone
America/Chicago
County
McHenry County County
Nearest Airport
Chicago O'Hare International (ORD) 22 miles away
Precipitation & Snow
Annual Rainfall40.4"
6% above US avg
Snowfall38.5"
Wettest Month (Aug)4.13"
Driest Month (Feb)1.22"
Air Quality
AQI Median
43.0
Rating
Good
Natural Hazard Risk
Overall Risk
Relatively Moderate
Risk Score
90.8 / 100
Social Vulnerability
10.6 / 100
Community Resilience
84.0 / 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 Low
Winter Weather
Relatively Moderate
Lightning
Relatively Moderate
Ice Storm
Relatively Low
Drought
Relatively Low
Cold Wave
Relatively High
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
100 km
10 km
Feb 10, 2010
2 km NW of Lily Lake, Illinois
M3.8
34 km
10 km
Sep 2, 1999
8 km W of Amboy, Illinois
M3.5
114 km
5 km
Nov 4, 2013
1 km SSW of Lyons, Illinois
M3.2
55 km
1 km
Jul 15, 2024
2 km WNW of Somonauk, Illinois
M3.1
74 km
10 km
Mar 25, 2015
3 km WNW of Lake in the Hills, Illinois
M2.9
13 km
6 km
Jun 10, 2013
4 km NNE of Virgil, Illinois
M2.6
33 km
5 km
Mar 15, 2025
6 km W of Dwight, Illinois
M2.6
126 km
5 km
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
558 tornadoes (EF0+) recorded within 100 km since 1950.
Strongest on record: EF5. Total: 107 fatalities, 2,292 injuries.
Date
Rating
Distance
Path
Fatalities
Aug 28, 1990
EF5
58 km
16.4 mi
29
Apr 9, 2015
EF4
97 km
30.1 mi
2
Apr 27, 1984
EF4
88 km
6.5 mi
1
Jun 29, 1979
EF4
75 km
5.4 mi
0
Jun 13, 1976
EF4
61 km
3.3 mi
2
Sep 28, 1972
EF4
30 km
5.2 mi
0
Apr 21, 1967
EF4
58 km
25.5 mi
24
Apr 21, 1967
EF4
67 km
15.0 mi
33
Apr 21, 1967
EF4
7 km
8.8 mi
1
Apr 11, 1965
EF4
14 km
9.1 mi
6
Jun 20, 2021
EF3
50 km
17.6 mi
0
Jun 22, 2015
EF3
100 km
16.3 mi
0
Jan 7, 2008
EF3
55 km
13.2 mi
0
Jan 7, 2008
EF3
41 km
10.8 mi
0
Mar 27, 1991
EF3
69 km
15.0 mi
0
Apr 27, 1984
EF3
72 km
9.0 mi
1
Jun 30, 1977
EF3
94 km
6.1 mi
0
Mar 12, 1976
EF3
64 km
22.6 mi
0
Nov 12, 1965
EF3
94 km
4.1 mi
0
Jul 19, 1963
EF3
43 km
10.6 mi
0
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Tsunami History
1 tsunami recorded within 500 km.
Highest wave on record: 3.0 m (10 ft).
Year
Location
Cause
Max Wave
Deaths
Distance
1954
MICHIGAN CITY, IN (LAKE MICHIGAN)
Avalanche
3.0 m
7
123 km
Source: NOAA/NCEI Historical Tsunami Database.
Wildfire History
10 wildfires (100+ acres) recorded within 100 km.
Largest: UNNAMED (1,741 acres, 2019).
Year
Name
Acres Burned
Distance
2019
UNNAMED
1,741
91 km
2019
UNNAMED
1,664
92 km
2021
NORTHEAST PRAIRIE UNIT 3
978
94 km
2024
NORTHEAST PRAIRIE 3 RX
938
92 km
2021
UNNAMED
738
91 km
2021
MIDDLE GRANT CREEK
700
92 km
2019
UNNAMED
698
91 km
2024
IBSP SOUTH F1 RX
690
41 km
2024
RX-HWY Y - SOUTH
553
96 km
2017
UNNAMED
549
92 km
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
Month
Avg Temperature
Precipitation
Summary
January
21°F (-6°C)
1.5 in
Coldest
February
25°F (-4°C)
1.2 in
Driest
March
36°F (2°C)
2.5 in
April
47°F (8°C)
3.6 in
May
58°F (15°C)
3.5 in
June
68°F (20°C)
4.1 in
July
72°F (22°C)
4.1 in
Warmest
August
71°F (21°C)
4.1 in
Wettest
September
63°F (17°C)
3.9 in
October
51°F (11°C)
2.4 in
November
38°F (3°C)
2.8 in
December
26°F (-4°C)
2.1 in
Fox River Grove has a seasonal temperature swing of 51°F / from 21°F in January to 72°F in July. Total annual precipitation is 35.7 inches, with August being the wettest month (4.1") and February the driest (1.2").