Weather & Climate in Waterloo, IL

Temperature, precipitation, air quality, natural hazards, and monthly weather data.

Waterloo enjoys a temperate climate with an average annual temperature of 56°F (13°C). Winters average 32°F in January while summers reach 78°F in July. The area gets 293 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 43.6 inches. The area receives 9.2 inches of snow annually. Air quality is rated Good with a median AQI of 43. The city sits at an elevation of 694 feet.

Temperature

32°F Jan (-0°C) 78°F Jul (25°C)

Annual Average	55.7°F
	3% above US avg
January Average	32°F (-0°C)
July Average	78°F (25°C)
Sunny Days	293 days/yr

Geography

Elevation	694 ft (212 m)
Area	7.7 sq mi (19.8 km²)
Population Density	1,334/sq mi
Coordinates	38.3412°N, 90.1527°W
Timezone	America/Chicago
County	Monroe County County
Nearest Airport	St Louis Lambert International (STL) 31 miles away

Precipitation & Snow

Annual Rainfall 43.6"

15% above US avg

Snowfall 9.2"

Wettest Month (May) 4.09"

Driest Month (Jan) 2.05"

Air Quality

AQI Median	43.0
Rating	Good

Natural Hazard Risk

Overall Risk	Very Low
Risk Score	41.9 / 100
Social Vulnerability	10.6 / 100
Community Resilience	94.9 / 100

Hazard Breakdown

Tornado	Relatively Low
Hurricane	Very Low
Earthquake	Relatively Low
Wildfire	Very Low
Flood	Very Low
Hail	Relatively Low
Strong Wind	Relatively Moderate
Heat Wave	Relatively Moderate
Winter Weather	Relatively Low
Lightning	Relatively Low
Ice Storm	Very Low
Drought	Relatively Low
Cold Wave	Relatively Low
Landslide	Relatively Low

Source: FEMA National Risk Index v1.20 (Dec 2025)

Earthquake History

52 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.8.

Sep 26, 1990	4 km SE of Chaffee, Missouri	M4.8	141 km	1 km
Feb 5, 1994	2 km WNW of Dongola, Illinois	M4.2	137 km	16 km
Jun 7, 2011	18 km NNW of Potosi, Missouri	M3.9	72 km	21 km
Mar 2, 1990	9 km NW of Vernon, Illinois	M3.4	103 km	0 km
Aug 27, 1993	5 km SSE of Olympian Village, Missouri	M3.3	37 km	22 km
Oct 24, 1990	5 km ENE of Woodlawn, Illinois	M3.2	103 km	1 km
Apr 6, 1994	2 km NE of Tamaroa, Illinois	M3.2	85 km	15 km
Jan 29, 1993	7 km WNW of Brownstown, Illinois	M3.2	124 km	5 km
May 2, 2003	10 km ENE of Thompsonville, Illinois	M3.2	137 km	0 km
Dec 27, 1992	2 km E of Pocahontas, Missouri	M3.2	105 km	10 km
Jul 1, 2017	9 km SSE of Mulberry Grove, Illinois	M3.1	98 km	17 km
Jan 23, 1991	3 km WSW of Logan, Illinois	M3.1	121 km	1 km
Mar 12, 2002	6 km S of Marble Hill, Missouri	M3.1	123 km	10 km
Jun 27, 2005	6 km E of Grand Tower, Illinois	M3.0	102 km	10 km
Mar 1, 2006	2 km N of Buncombe, Illinois	M3.0	139 km	6 km
Feb 28, 1994	5 km NW of Harrison, Illinois	M3.0	89 km	5 km
May 18, 2006	9 km SSE of De Soto, Missouri	M2.9	46 km	6 km
Sep 5, 2004	3 km WNW of Saint Peter, Illinois	M2.9	125 km	33 km
Sep 5, 1995	3 km N of Woodlawn, Illinois	M2.9	97 km	4 km
Jul 8, 2003	1 km N of Leasburg, Missouri	M2.9	103 km	4 km

Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.

Tornado History

618 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF5. Total: 90 fatalities, 1,452 injuries.

Date	Rating	Distance	Path	Fatalities
Dec 18, 1957	EF5	84 km	5.4 mi	1
Feb 28, 2017	EF4	70 km	53.5 mi	1
Nov 17, 2013	EF4	62 km	10.6 mi	2
Apr 22, 2011	EF4	53 km	21.3 mi	0
Sep 22, 2006	EF4	79 km	27.5 mi	0
Apr 3, 1981	EF4	42 km	11.9 mi	0
Jun 22, 1969	EF4	76 km	15.1 mi	4
Jun 22, 1969	EF4	94 km	20.2 mi	2
Jan 24, 1967	EF4	51 km	25.0 mi	3
Feb 10, 1959	EF4	44 km	23.9 mi	21
Dec 18, 1957	EF4	93 km	28.3 mi	11
Dec 18, 1957	EF4	94 km	16.8 mi	1
Feb 24, 1956	EF4	68 km	77.6 mi	6
Dec 10, 2021	EF3	72 km	24.8 mi	1
Dec 10, 2021	EF3	47 km	4.2 mi	6
Oct 24, 2021	EF3	91 km	18.8 mi	0
Oct 24, 2021	EF3	74 km	16.7 mi	0
May 31, 2013	EF3	51 km	10.6 mi	0
May 31, 2013	EF3	65 km	31.7 mi	0
Dec 31, 2010	EF3	32 km	6.7 mi	1

Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).

Wildfire History

20 wildfires (100+ acres) recorded within 100 km. Largest: SMITH MILL HOLLOW (3,978 acres, 2022).

Year	Name	Acres Burned	Distance
2022	SMITH MILL HOLLOW	3,978	86 km
2021	COUNCIL BLUFF	3,035	98 km
2024	COUNCIL BLUFF WEST RX	2,846	98 km
2005	UNNAMED	2,751	95 km
2019	UNNAMED	2,688	89 km
2010	COUNCIL BLUFF LAKE	2,651	98 km
2006	UNNAMED	2,512	98 km
2021	BEAR PAW	2,080	96 km
2024	BEAR PAW RX	2,067	96 km
2004	CICERO CREEK	1,846	83 km
2021	BERRYMAN BLOCK B AND C	1,728	91 km
2015	UNNAMED	1,586	95 km
2010	DELBRIDGE SOUTH	1,574	95 km
2000	UNNAMED	1,552	88 km
1999	UNNAMED	1,483	88 km
2024	HARMON SPRING RX	1,330	89 km
2018	UNNAMED	1,285	89 km
2019	KINKAID RX	1,215	86 km
2013	UNNAMED	1,196	96 km
2022	JOHNSON MOUNTAIN	1,155	96 km

Source: NIFC/IRWIN Wildfire Records (100+ acres).

Monthly Weather

Month	Avg Temperature	Precipitation	Summary
January	32°F (-0°C)	2.1 in	Coldest, Driest
February	34°F (1°C)	2.3 in
March	44°F (7°C)	3.6 in
April	55°F (13°C)	3.7 in
May	65°F (18°C)	4.1 in	Wettest
June	74°F (23°C)	3.7 in
July	78°F (25°C)	3.8 in	Warmest
August	76°F (24°C)	3.2 in
September	69°F (20°C)	3.4 in
October	57°F (14°C)	2.8 in
November	45°F (7°C)	3.5 in
December	34°F (1°C)	3.1 in

Waterloo has a seasonal temperature swing of 46°F / from 32°F in January to 78°F in July. Total annual precipitation is 39.2 inches, with May being the wettest month (4.1") and January the driest (2.1").

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