Weather & Climate in Walnut, IL

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

Walnut experiences four distinct seasons with an average annual temperature of 49°F (10°C). Winters average 21°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 36.8 inches. The area receives 35.9 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 709 feet.

Temperature

21°F Jan (-6°C) 73°F Jul (23°C)

Annual Average	49.3°F
	9% below US avg
January Average	21°F (-6°C)
July Average	73°F (23°C)
Sunny Days	275 days/yr

Geography

Elevation	709 ft (216 m)
Area	0.3 sq mi (0.8 km²)
Population Density	1,753/sq mi
Coordinates	41.5571°N, 89.5913°W
Timezone	America/Chicago
County	Bureau County County
Nearest Airport	Illinois Valley Regional-Walter A Duncan Field (VYS) 27 miles away

Precipitation & Snow

Annual Rainfall 36.8"

3% below US avg

Snowfall 35.9"

Wettest Month (Jun) 4.57"

Driest Month (Feb) 1.30"

Air Quality

AQI Median	43.0
Rating	Good

Natural Hazard Risk

Overall Risk	Relatively Low
Risk Score	62.3 / 100
Social Vulnerability	41.7 / 100
Community Resilience	80.1 / 100

Hazard Breakdown

Tornado	Relatively Moderate
Hurricane	Very Low
Earthquake	Relatively Low
Wildfire	Very Low
Flood	Relatively Low
Hail	Relatively Moderate
Strong Wind	Relatively Moderate
Heat Wave	Relatively Low
Winter Weather	Relatively Low
Lightning	Relatively Low
Ice Storm	Relatively Moderate
Drought	Relatively High
Cold Wave	Relatively Moderate
Landslide	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	59 km	10 km
Feb 10, 2010	2 km NW of Lily Lake, Illinois	M3.8	102 km	10 km
Sep 2, 1999	8 km W of Amboy, Illinois	M3.5	23 km	5 km
Nov 4, 2013	1 km SSW of Lyons, Illinois	M3.2	149 km	1 km
Jul 15, 2024	2 km WNW of Somonauk, Illinois	M3.1	74 km	10 km
Mar 25, 2015	3 km WNW of Lake in the Hills, Illinois	M2.9	123 km	6 km
Jun 10, 2013	4 km NNE of Virgil, Illinois	M2.6	102 km	5 km
Mar 15, 2025	6 km W of Dwight, Illinois	M2.6	105 km	5 km

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

Tornado History

614 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 43 fatalities, 777 injuries.

Date	Rating	Distance	Path	Fatalities
Apr 9, 2015	EF4	41 km	30.1 mi	2
Jul 13, 2004	EF4	87 km	9.6 mi	0
Mar 29, 1981	EF4	33 km	5.1 mi	0
Jun 29, 1976	EF4	85 km	4.9 mi	0
Apr 21, 1967	EF4	92 km	25.5 mi	24
Feb 28, 2017	EF3	59 km	11.5 mi	2
Feb 28, 2017	EF3	74 km	17.8 mi	0
Jun 5, 2010	EF3	88 km	8.6 mi	0
Apr 20, 2004	EF3	43 km	15.8 mi	8
May 9, 1995	EF3	34 km	22.0 mi	0
Mar 13, 1990	EF3	58 km	15.5 mi	0
Aug 5, 1979	EF3	52 km	5.7 mi	0
Jun 30, 1977	EF3	49 km	6.1 mi	0
Mar 4, 1976	EF3	40 km	0.8 mi	0
Jun 20, 1974	EF3	73 km	10.6 mi	1
Jun 14, 1974	EF3	92 km	48.6 mi	0
May 13, 1974	EF3	84 km	3.6 mi	0
Jul 17, 1972	EF3	54 km	81.5 mi	0
Jan 24, 1967	EF3	66 km	7.4 mi	0
Apr 19, 1966	EF3	76 km	2.0 mi	0

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

Monthly Weather

Month	Avg Temperature	Precipitation	Summary
January	21°F (-6°C)	1.4 in	Coldest
February	25°F (-4°C)	1.3 in	Driest
March	37°F (3°C)	2.6 in
April	49°F (9°C)	3.6 in
May	61°F (16°C)	4.4 in
June	70°F (21°C)	4.6 in	Wettest
July	73°F (23°C)	3.7 in	Warmest
August	71°F (22°C)	4.3 in
September	64°F (18°C)	3.6 in
October	52°F (11°C)	2.8 in
November	38°F (4°C)	2.6 in
December	26°F (-4°C)	2.1 in

Walnut has a seasonal temperature swing of 52°F / from 21°F in January to 73°F in July. Total annual precipitation is 36.9 inches, with June being the wettest month (4.6") and February the driest (1.3").

View full profile of Walnut, IL →