Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Bonfield experiences four distinct seasons with an average annual temperature of 49°F (10°C). Winters average 22°F in January while summers reach 73°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 37.7 inches. The area receives 23.3 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 623 feet.
Temperature
22°F Jan (-5°C)73°F Jul (23°C)
Annual Average
49.3°F
9% below US avg
January Average
22°F (-5°C)
July Average
73°F (23°C)
Sunny Days
275 days/yr
Geography
Elevation
623 ft (190 m)
Area
0.2 sq mi (0.5 km²)
Population Density
967/sq mi
Coordinates
41.1450°N, 88.0540°W
Timezone
America/Chicago
County
Grundy County County
Nearest Airport
Joliet Regional (JOT) 27 miles away
Precipitation & Snow
Annual Rainfall37.7"
1% below US avg
Snowfall23.3"
Wettest Month (May)4.02"
Driest Month (Feb)1.46"
Air Quality
AQI Median
43.0
Rating
Good
Natural Hazard Risk
Overall Risk
Relatively Low
Risk Score
66.5 / 100
Social Vulnerability
10.6 / 100
Community Resilience
99.5 / 100
Hazard Breakdown
Tornado
Relatively Moderate
Hurricane
Very Low
Earthquake
Very Low
Wildfire
Very Low
Flood
Relatively Low
Hail
Very Low
Strong Wind
Relatively Moderate
Heat Wave
Relatively Low
Winter Weather
Relatively Low
Lightning
Very Low
Ice Storm
Very Low
Drought
Relatively Low
Cold Wave
Relatively High
Landslide
Very Low
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
9 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
79 km
10 km
Feb 10, 2010
2 km NW of Lily Lake, Illinois
M3.8
99 km
10 km
Sep 2, 1999
8 km W of Amboy, Illinois
M3.5
132 km
5 km
Nov 4, 2013
1 km SSW of Lyons, Illinois
M3.2
75 km
1 km
Dec 17, 1990
Illinois-Indiana border region
M3.2
147 km
10 km
Jul 15, 2024
2 km WNW of Somonauk, Illinois
M3.1
78 km
10 km
Mar 25, 2015
3 km WNW of Lake in the Hills, Illinois
M2.9
119 km
6 km
Jun 10, 2013
4 km NNE of Virgil, Illinois
M2.6
101 km
5 km
Mar 15, 2025
6 km W of Dwight, Illinois
M2.6
38 km
5 km
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
688 tornadoes (EF0+) recorded within 100 km since 1950.
Strongest on record: EF5. Total: 80 fatalities, 1,526 injuries.
Date
Rating
Distance
Path
Fatalities
Aug 28, 1990
EF5
64 km
16.4 mi
29
Jun 29, 1979
EF4
44 km
5.4 mi
0
Jun 13, 1976
EF4
59 km
3.3 mi
2
Apr 21, 1967
EF4
61 km
15.0 mi
33
Apr 17, 1963
EF4
6 km
57.3 mi
1
Jun 20, 2021
EF3
68 km
17.6 mi
0
Feb 28, 2017
EF3
78 km
11.5 mi
2
Jun 22, 2015
EF3
33 km
16.3 mi
0
Jun 5, 2010
EF3
27 km
7.8 mi
0
Jun 5, 2010
EF3
57 km
8.6 mi
0
Mar 27, 1991
EF3
49 km
15.0 mi
0
Apr 27, 1984
EF3
51 km
9.0 mi
1
Apr 2, 1982
EF3
12 km
12.0 mi
0
Jun 30, 1977
EF3
93 km
6.1 mi
0
Mar 12, 1976
EF3
34 km
38.5 mi
1
Mar 12, 1976
EF3
59 km
22.6 mi
0
Jun 20, 1974
EF3
55 km
4.5 mi
0
Apr 3, 1974
EF3
84 km
7.4 mi
0
May 15, 1968
EF3
66 km
7.1 mi
0
Oct 24, 1967
EF3
83 km
0.1 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
116 km
Source: NOAA/NCEI Historical Tsunami Database.
Wildfire History
12 wildfires (100+ acres) recorded within 100 km.
Largest: UNNAMED (1,741 acres, 2019).
Year
Name
Acres Burned
Distance
2019
UNNAMED
1,741
28 km
2019
UNNAMED
1,664
26 km
2000
UNNAMED
1,602
44 km
2021
NORTHEAST PRAIRIE UNIT 3
978
25 km
2024
NORTHEAST PRAIRIE 3 RX
938
26 km
1986
OGDEN DUNS
863
87 km
2021
UNNAMED
738
27 km
2021
MIDDLE GRANT CREEK
700
26 km
2019
UNNAMED
698
27 km
2021
21-INDU TOLLESTON DUNES EAST
594
88 km
2017
UNNAMED
549
27 km
2017
17 INDU COWLES DUNES
522
97 km
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
Month
Avg Temperature
Precipitation
Summary
January
22°F (-5°C)
1.5 in
Coldest
February
27°F (-3°C)
1.5 in
Driest
March
38°F (3°C)
2.8 in
April
50°F (10°C)
3.7 in
May
61°F (16°C)
4.0 in
Wettest
June
71°F (21°C)
4.0 in
July
73°F (23°C)
3.9 in
Warmest
August
72°F (22°C)
3.5 in
September
65°F (18°C)
3.5 in
October
53°F (12°C)
2.7 in
November
40°F (5°C)
3.0 in
December
28°F (-2°C)
2.6 in
Bonfield has a seasonal temperature swing of 51°F / from 22°F in January to 73°F in July. Total annual precipitation is 36.7 inches, with May being the wettest month (4.0") and February the driest (1.5").