Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Rock Island Arsenal experiences four distinct seasons with an average annual temperature of 50°F (10°C). Winters average 22°F in January while summers reach 74°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 38.8 inches. Air quality is rated Good with a median AQI of 43. The city sits at an elevation of 581 feet.
Temperature
22°F Jan (-5°C)74°F Jul (24°C)
Annual Average
50.3°F
7% below US avg
January Average
22°F (-5°C)
July Average
74°F (24°C)
Sunny Days
275 days/yr
Geography
Elevation
581 ft (177 m)
Area
2.6 sq mi (6.7 km²)
Population Density
237/sq mi
Coordinates
41.5170°N, 90.5397°W
Timezone
America/Chicago
County
Rock Island County County
Nearest Airport
Quad Cities International (MLI) 5 miles away
Precipitation & Snow
Annual Rainfall38.8"
2% above US avg
Wettest Month (Jul)4.41"
Driest Month (Feb)1.10"
Air Quality
AQI Median
43.0
Rating
Good
Natural Hazard Risk
Overall Risk
Relatively Moderate
Risk Score
84.1 / 100
Social Vulnerability
60.2 / 100
Community Resilience
87.3 / 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 Moderate
Winter Weather
Relatively High
Lightning
Relatively High
Ice Storm
Relatively Moderate
Drought
Relatively Moderate
Cold Wave
Relatively High
Landslide
Relatively Low
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
2 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
137 km
10 km
Sep 2, 1999
8 km W of Amboy, Illinois
M3.5
95 km
5 km
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
638 tornadoes (EF0+) recorded within 100 km since 1950.
Strongest on record: EF4. Total: 7 fatalities, 207 injuries.
Date
Rating
Distance
Path
Fatalities
Mar 29, 1981
EF4
52 km
5.1 mi
0
Apr 11, 1965
EF4
49 km
91.5 mi
1
Jun 1, 2007
EF3
61 km
15.8 mi
0
May 9, 1995
EF3
28 km
10.0 mi
0
May 9, 1995
EF3
66 km
22.0 mi
0
Jun 19, 1993
EF3
91 km
14.0 mi
0
Jul 13, 1992
EF3
89 km
5.0 mi
0
Mar 13, 1990
EF3
24 km
15.5 mi
0
May 8, 1988
EF3
33 km
32.0 mi
0
Aug 5, 1979
EF3
97 km
5.7 mi
0
Aug 15, 1978
EF3
34 km
6.4 mi
0
Mar 4, 1976
EF3
88 km
0.8 mi
0
Jun 13, 1975
EF3
96 km
6.6 mi
0
Jun 20, 1974
EF3
56 km
10.6 mi
1
Jun 14, 1974
EF3
19 km
48.6 mi
0
May 13, 1974
EF3
13 km
3.6 mi
0
Jul 17, 1972
EF3
91 km
81.5 mi
0
Jan 24, 1967
EF3
73 km
7.4 mi
0
Apr 19, 1966
EF3
4 km
2.0 mi
0
Aug 25, 1965
EF3
96 km
3.0 mi
0
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Wildfire History
5 wildfires (100+ acres) recorded within 100 km.
Largest: UNIT 3 (1,206 acres, 1999).
Year
Name
Acres Burned
Distance
1999
UNIT 3
1,206
64 km
2002
HSB 03 2
1,130
65 km
2000
DESTRUST A
756
64 km
2006
HSB 003
674
65 km
2004
HSB 009
608
64 km
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
Month
Avg Temperature
Precipitation
Summary
January
22°F (-5°C)
1.4 in
Coldest
February
26°F (-3°C)
1.1 in
Driest
March
38°F (3°C)
2.5 in
April
50°F (10°C)
3.6 in
May
62°F (17°C)
3.9 in
June
71°F (22°C)
4.3 in
July
74°F (24°C)
4.4 in
Warmest, Wettest
August
73°F (23°C)
4.1 in
September
65°F (18°C)
3.9 in
October
53°F (12°C)
2.7 in
November
38°F (4°C)
2.3 in
December
26°F (-3°C)
1.9 in
Rock Island Arsenal has a seasonal temperature swing of 52°F / from 22°F in January to 74°F in July. Total annual precipitation is 36.0 inches, with July being the wettest month (4.4") and February the driest (1.1").