Weather & Climate in Chester, IL

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

Chester enjoys a temperate climate with an average annual temperature of 56°F (14°C). Winters average 32°F in January while summers reach 79°F in July. The area gets 305 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 42.8 inches. The area receives 4.3 inches of snow annually. Air quality is rated Good with a median AQI of 43. The city sits at an elevation of 568 feet.

Temperature

32°F Jan (0°C) 79°F Jul (26°C)

Annual Average	56.4°F
	4% above US avg
January Average	32°F (0°C)
July Average	79°F (26°C)
Sunny Days	305 days/yr

Geography

Elevation	568 ft (173 m)
Area	5.8 sq mi (14.9 km²)
Population Density	1,184/sq mi
Coordinates	37.9258°N, 89.8277°W
Timezone	America/Chicago
County	Perry County County
Nearest Airport	Farmington Regional (FAM) 32 miles away

Precipitation & Snow

Annual Rainfall 42.8"

13% above US avg

Snowfall 4.3"

Wettest Month (May) 4.41"

Driest Month (Jan) 2.28"

Air Quality

AQI Median	43.0
Rating	Good

Natural Hazard Risk

Overall Risk	Relatively Low
Risk Score	46.2 / 100
Social Vulnerability	14.4 / 100
Community Resilience	79.4 / 100

Hazard Breakdown

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

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

Earthquake History

145 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	88 km	1 km
Feb 5, 1994	2 km WNW of Dongola, Illinois	M4.2	84 km	16 km
Jun 6, 2003	1 km NE of Bardwell, Kentucky	M4.0	138 km	3 km
Feb 21, 2012	4 km SSE of Bertrand, Missouri	M3.9	122 km	8 km
Jun 7, 2011	18 km NNW of Potosi, Missouri	M3.9	96 km	21 km
Mar 2, 2010	2 km ENE of East Prairie, Missouri	M3.7	133 km	8 km
Jun 20, 2005	4 km WSW of Blandville, Kentucky	M3.6	133 km	19 km
Sep 22, 2011	6 km E of Grandin, Missouri	M3.6	148 km	11 km
Jan 2, 2006	3 km NNE of Eldorado, Illinois	M3.6	124 km	7 km
Mar 15, 2017	9 km ESE of Wyatt, Missouri	M3.6	132 km	8 km
Jun 15, 2004	3 km S of Canalou, Missouri	M3.5	134 km	5 km
May 1, 2016	5 km SE of New Grand Chain, Illinois	M3.5	108 km	16 km
Jul 16, 2004	6 km SE of Wyatt, Missouri	M3.5	131 km	4 km
Mar 2, 1990	9 km NW of Vernon, Illinois	M3.4	118 km	0 km
May 30, 2015	4 km ENE of Geff, Illinois	M3.4	142 km	26 km
Sep 26, 1994	4 km ENE of Blandville, Kentucky	M3.4	134 km	13 km
Aug 27, 1993	5 km SSE of Olympian Village, Missouri	M3.3	57 km	22 km
Feb 6, 1993	6 km NNW of Catron, Missouri	M3.3	141 km	8 km
May 16, 2017	9 km ESE of Wyatt, Missouri	M3.3	133 km	9 km
Apr 6, 1994	2 km NE of Tamaroa, Illinois	M3.2	60 km	15 km

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

Tornado History

616 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF5. Total: 98 fatalities, 1,300 injuries.

Date	Rating	Distance	Path	Fatalities
Dec 18, 1957	EF5	53 km	5.4 mi	1
Feb 28, 2017	EF4	27 km	53.5 mi	1
Nov 17, 2013	EF4	64 km	10.6 mi	2
Sep 22, 2006	EF4	27 km	27.5 mi	0
May 29, 1982	EF4	63 km	17.0 mi	10
Apr 3, 1981	EF4	92 km	11.9 mi	0
Jun 22, 1969	EF4	67 km	15.1 mi	4
Feb 10, 1959	EF4	95 km	23.9 mi	21
Dec 18, 1957	EF4	40 km	28.3 mi	11
Dec 18, 1957	EF4	76 km	16.8 mi	1
May 26, 2024	EF3	81 km	4.9 mi	0
Dec 10, 2021	EF3	95 km	4.2 mi	6
Oct 24, 2021	EF3	65 km	18.8 mi	0
Oct 24, 2021	EF3	57 km	16.7 mi	0
Dec 31, 2010	EF3	84 km	6.7 mi	1
Mar 11, 2006	EF3	49 km	5.1 mi	0
Mar 11, 2006	EF3	19 km	53.5 mi	2
May 6, 2003	EF3	62 km	2.0 mi	0
Apr 28, 2002	EF3	76 km	19.3 mi	1
Apr 27, 2002	EF3	81 km	4.0 mi	1

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

Wildfire History

20 wildfires (100+ acres) recorded within 100 km. Largest: RED SHALE UNIT RX (2,123 acres, 2021).

Year	Name	Acres Burned	Distance
2021	RED SHALE UNIT RX	2,123	71 km
2014	UNNAMED	1,627	72 km
2019	ATWOOD RIDGE RX	1,622	72 km
2000	UNNAMED	1,552	77 km
1999	UNNAMED	1,483	77 km
2020	UNNAMED	1,334	89 km
2000	UNNAMED	1,260	91 km
2024	RED SHALE RX	1,259	71 km
2017	UNNAMED	1,257	79 km
2021	OZARK HILL PRAIRIE RX	1,235	79 km
2019	KINKAID RX	1,215	36 km
2000	UNNAMED	1,187	93 km
2022	JOHNSON MOUNTAIN	1,155	97 km
2022	KINKAID STATE FISH AND WILDLIFE AREA RX	1,115	36 km
2024	RENAULT	1,085	92 km
2021	COUNCIL BLUFF BEACH	1,059	99 km
2024	JOHNSON MTN BLOCK 2 RX	1,033	99 km
2021	STATE OF ILLINOIS TRACT RX	1,011	26 km
2022	BEAN RIDGE RX	955	84 km
2021	MILL CREEK RX	898	61 km

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

Monthly Weather

Month	Avg Temperature	Precipitation	Summary
January	32°F (0°C)	2.3 in	Coldest, Driest
February	35°F (2°C)	2.6 in
March	45°F (7°C)	4.2 in
April	56°F (13°C)	3.9 in
May	65°F (18°C)	4.4 in	Wettest
June	74°F (23°C)	3.8 in
July	79°F (26°C)	4.1 in	Warmest
August	76°F (25°C)	3.5 in
September	69°F (21°C)	3.4 in
October	58°F (14°C)	2.9 in
November	46°F (8°C)	4.1 in
December	36°F (2°C)	3.5 in

Chester has a seasonal temperature swing of 47°F / from 32°F in January to 79°F in July. Total annual precipitation is 42.6 inches, with May being the wettest month (4.4") and January the driest (2.3").

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