Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Hillside experiences four distinct seasons with an average annual temperature of 51°F (11°C). Winters average 25°F in January while summers reach 75°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 37.9 inches. The area receives 38.4 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 657 feet.
Temperature
25°F Jan (-4°C)75°F Jul (24°C)
Annual Average
51.3°F
5% below US avg
January Average
25°F (-4°C)
July Average
75°F (24°C)
Sunny Days
275 days/yr
Geography
Elevation
657 ft (200 m)
Area
1.2 sq mi (3.2 km²)
Population Density
2,566/sq mi
Coordinates
41.8675°N, 87.9018°W
Timezone
America/Chicago
County
Cook County County
Nearest Airport
Chicago O'Hare International (ORD) 8 miles away
Precipitation & Snow
Annual Rainfall37.9"
0% below US avg
Snowfall38.4"
Wettest Month (Aug)4.17"
Driest Month (Feb)1.54"
Air Quality
AQI Median
43.0
Rating
Good
Natural Hazard Risk
Overall Risk
Very High
Risk Score
100.0 / 100
Social Vulnerability
61.7 / 100
Community Resilience
73.3 / 100
Hazard Breakdown
Tornado
Very High
Hurricane
Very Low
Earthquake
Relatively High
Wildfire
Very Low
Flood
Very High
Hail
Relatively High
Strong Wind
Very High
Heat Wave
Very High
Winter Weather
Very High
Lightning
Very High
Ice Storm
Very High
Drought
Very Low
Cold Wave
Very High
Landslide
Very Low
Coastal Flood
Relatively 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
95 km
10 km
Feb 10, 2010
2 km NW of Lily Lake, Illinois
M3.8
51 km
10 km
Sep 2, 1999
8 km W of Amboy, Illinois
M3.5
128 km
5 km
Nov 4, 2013
1 km SSW of Lyons, Illinois
M3.2
10 km
1 km
Jul 15, 2024
2 km WNW of Somonauk, Illinois
M3.1
72 km
10 km
Mar 25, 2015
3 km WNW of Lake in the Hills, Illinois
M2.9
52 km
6 km
Jun 10, 2013
4 km NNE of Virgil, Illinois
M2.6
52 km
5 km
Mar 15, 2025
6 km W of Dwight, Illinois
M2.6
100 km
5 km
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
557 tornadoes (EF0+) recorded within 100 km since 1950.
Strongest on record: EF5. Total: 108 fatalities, 2,153 injuries.
Date
Rating
Distance
Path
Fatalities
Aug 28, 1990
EF5
43 km
16.4 mi
29
Jun 29, 1979
EF4
47 km
5.4 mi
0
Jun 13, 1976
EF4
23 km
3.3 mi
2
Sep 28, 1972
EF4
46 km
5.2 mi
0
Apr 21, 1967
EF4
44 km
8.8 mi
1
Apr 21, 1967
EF4
93 km
25.5 mi
24
Apr 21, 1967
EF4
23 km
15.0 mi
33
Apr 11, 1965
EF4
56 km
9.1 mi
6
Apr 17, 1963
EF4
78 km
57.3 mi
1
Jun 20, 2021
EF3
28 km
17.6 mi
0
Jun 22, 2015
EF3
74 km
16.3 mi
0
Jun 5, 2010
EF3
90 km
7.8 mi
0
Jan 7, 2008
EF3
84 km
10.8 mi
0
Jan 7, 2008
EF3
96 km
13.2 mi
0
Mar 27, 1991
EF3
36 km
15.0 mi
0
Apr 27, 1984
EF3
50 km
9.0 mi
1
Apr 2, 1982
EF3
91 km
12.0 mi
0
Jun 30, 1977
EF3
97 km
6.1 mi
0
Mar 12, 1976
EF3
80 km
12.6 mi
0
Mar 12, 1976
EF3
98 km
38.5 mi
1
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
87 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
59 km
2019
UNNAMED
1,664
58 km
2021
NORTHEAST PRAIRIE UNIT 3
978
57 km
2024
NORTHEAST PRAIRIE 3 RX
938
55 km
1986
OGDEN DUNS
863
64 km
2021
UNNAMED
738
55 km
2021
MIDDLE GRANT CREEK
700
59 km
2019
UNNAMED
698
55 km
2024
IBSP SOUTH F1 RX
690
60 km
2021
21-INDU TOLLESTON DUNES EAST
594
64 km
2017
UNNAMED
549
59 km
2017
17 INDU COWLES DUNES
522
71 km
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
Month
Avg Temperature
Precipitation
Summary
January
25°F (-4°C)
1.7 in
Coldest
February
27°F (-3°C)
1.5 in
Driest
March
38°F (3°C)
2.6 in
April
49°F (9°C)
3.7 in
May
60°F (16°C)
3.6 in
June
70°F (21°C)
3.9 in
July
75°F (24°C)
3.7 in
Warmest
August
73°F (23°C)
4.2 in
Wettest
September
65°F (18°C)
3.5 in
October
53°F (12°C)
2.7 in
November
40°F (4°C)
3.0 in
December
28°F (-2°C)
2.4 in
Hillside has a seasonal temperature swing of 50°F / from 25°F in January to 75°F in July. Total annual precipitation is 36.7 inches, with August being the wettest month (4.2") and February the driest (1.5").