Temperature, precipitation, air quality, natural hazards, and monthly weather data.
South Beloit experiences four distinct seasons with an average annual temperature of 49°F (10°C). Winters average 22°F in January while summers reach 74°F in July. The area gets 260 sunny days per year, above the national average. Annual precipitation totals 37.2 inches. The area receives 37.1 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 770 feet.
Temperature
22°F Jan (-6°C)74°F Jul (23°C)
Annual Average
49.4°F
9% below US avg
January Average
22°F (-6°C)
July Average
74°F (23°C)
Sunny Days
260 days/yr
Geography
Elevation
770 ft (235 m)
Area
2.4 sq mi (6.1 km²)
Population Density
1,285/sq mi
Coordinates
42.4848°N, 89.0274°W
Timezone
America/Chicago
County
Winnebago County County
Nearest Airport
Southern Wisconsin Regional (JVL) 9 miles away
Precipitation & Snow
Annual Rainfall37.2"
2% below US avg
Snowfall37.1"
Wettest Month (Jun)4.09"
Driest Month (Feb)1.10"
Air Quality
AQI Median
43.0
Rating
Good
Natural Hazard Risk
Overall Risk
Relatively Moderate
Risk Score
92.4 / 100
Social Vulnerability
38.9 / 100
Community Resilience
68.5 / 100
Hazard Breakdown
Tornado
Relatively High
Hurricane
Very Low
Earthquake
Relatively Low
Wildfire
Very Low
Flood
Relatively High
Hail
Relatively High
Strong Wind
Relatively High
Heat Wave
Relatively Moderate
Winter Weather
Relatively Moderate
Lightning
Relatively High
Ice Storm
Relatively High
Drought
Relatively Low
Cold Wave
Relatively High
Landslide
Very Low
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
7 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
114 km
10 km
Feb 10, 2010
2 km NW of Lily Lake, Illinois
M3.8
72 km
10 km
Sep 2, 1999
8 km W of Amboy, Illinois
M3.5
91 km
5 km
Nov 4, 2013
1 km SSW of Lyons, Illinois
M3.2
125 km
1 km
Jul 15, 2024
2 km WNW of Somonauk, Illinois
M3.1
97 km
10 km
Mar 25, 2015
3 km WNW of Lake in the Hills, Illinois
M2.9
64 km
6 km
Jun 10, 2013
4 km NNE of Virgil, Illinois
M2.6
70 km
5 km
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
589 tornadoes (EF0+) recorded within 100 km since 1950.
Strongest on record: EF5. Total: 54 fatalities, 1,222 injuries.
Date
Rating
Distance
Path
Fatalities
Jun 7, 1984
EF5
95 km
36.0 mi
9
Apr 9, 2015
EF4
74 km
30.1 mi
2
Apr 27, 1984
EF4
77 km
6.5 mi
1
Sep 28, 1972
EF4
98 km
5.2 mi
0
Apr 21, 1967
EF4
31 km
25.5 mi
24
Apr 21, 1967
EF4
73 km
8.8 mi
1
Apr 11, 1965
EF4
61 km
9.1 mi
6
Jun 16, 2014
EF3
72 km
1.0 mi
0
Jan 7, 2008
EF3
19 km
13.2 mi
0
Jan 7, 2008
EF3
58 km
10.8 mi
0
Aug 18, 2005
EF3
59 km
18.6 mi
1
Jun 17, 1992
EF3
60 km
16.0 mi
0
May 8, 1988
EF3
99 km
16.0 mi
0
Jun 5, 1980
EF3
75 km
10.7 mi
0
Aug 5, 1979
EF3
69 km
5.7 mi
0
Jun 4, 1975
EF3
85 km
2.3 mi
0
Aug 2, 1967
EF3
80 km
0.1 mi
2
Apr 16, 1967
EF3
74 km
27.8 mi
0
Jan 24, 1967
EF3
31 km
24.9 mi
0
Jan 24, 1967
EF3
96 km
7.4 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
100 km
2024
RX-HWY Y - SOUTH
553
58 km
2009
COLD SPRINGS
552
54 km
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
Month
Avg Temperature
Precipitation
Summary
January
22°F (-6°C)
1.3 in
Coldest
February
24°F (-5°C)
1.1 in
Driest
March
35°F (2°C)
2.4 in
April
47°F (9°C)
3.4 in
May
59°F (15°C)
3.3 in
June
68°F (20°C)
4.1 in
Wettest
July
74°F (23°C)
3.9 in
Warmest
August
70°F (21°C)
4.1 in
September
62°F (17°C)
3.9 in
October
51°F (10°C)
2.6 in
November
37°F (3°C)
2.5 in
December
24°F (-4°C)
1.9 in
South Beloit has a seasonal temperature swing of 52°F / from 22°F in January to 74°F in July. Total annual precipitation is 34.3 inches, with June being the wettest month (4.1") and February the driest (1.1").