Chester, IL Weather Forecast & Alerts

Current conditions, 5-day forecast, and active NWS weather alerts for Chester, IL.

Current Conditions — Chester, IL

SPARTA (KSAR)

Clear

65.1 F
Humidity:99%
Wind Speed: 4.7 mph
Barometer:29.82 in
Dewpoint:64.9 F
Visibility:10.00 mi
Precip:--
Heat Index:NA
Wind Chill:NA
Apr 27 2026, 11:10 PM CDT
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5-Day Forecast — Chester, IL

Friday

High 64 °F
Partly Sunny
Friday
Night
Low 42 °F
Slight Chance of Rain
Saturday

High 60 °F
Isolated T-storm
Saturday
Night
Low 39 °F
Mostly Clear
Sunday

High 73 °F
Forecast Missing
Sunday
Night
Low 55 °F
Partly Cloudy
Monday

High 80 °F
Isolated T-storm
Monday
Night
Low 57 °F
Chance of Showers
Tuesday

High 73 °F
Chance of T-storms

Detailed Forecast — Chester, IL

Friday
Partly Sunny. High near 64°F. Wind 6 to 9 mph, with gusts as high as 15 mph.
Friday Night
Slight Chance of Rain. Low around 42°F. Wind 2 to 3 mph, with gusts as high as 7 mph.
Saturday
Isolated T-storm. High near 60°F. Wind 5 to 9 mph, with gusts as high as 15 mph.
Saturday Night
Mostly Clear. Low around 39°F. Wind 1 to 2 mph, with gusts as high as 5 mph.
Sunday
Sunny. High near 73°F. Wind 8 to 12 mph, with gusts as high as 20 mph.
Sunday Night
Partly Cloudy. Low around 55°F. Wind around 10 mph, with gusts as high as 17 mph.
Monday
Isolated T-storm. High near 80°F. Wind 14 to 16 mph, with gusts as high as 23 mph.
Monday Night
Chance of Showers. Low around 57°F. Wind around 13 mph, with gusts as high as 20 mph.
Tuesday
Chance of Thunderstorms. High near 73°F. Wind 15 to 20 mph, with gusts as high as 24 mph.
Tuesday Night
Thunderstorms Likely. Low around 51°F. Wind around 13 mph, with gusts as high as 15 mph.
Wednesday
Chance of Thunderstorms. High near 68°F. Wind 10 to 12 mph, with gusts as high as 17 mph.
Wednesday Night
Partly Cloudy. Low around 44°F. Wind around 7 mph, with gusts as high as 12 mph.
Thursday
Partly Sunny. High near 66°F. Wind 8 to 12 mph, with gusts as high as 20 mph.
IL Radar
Current Radar • IL
Day 1 Outlook • May 1, 2026

Observation History — Chester, IL

Time Wind
(mph)		 Vis
(mi)		 Weather Precip (in) Temperature (F) Relative
Humidity		 Wind
Chill
(F)		 Heat
Index
(F)		 Pressure
Air Dwpt altimeter
(in)		 sea level
(mb)
11:10 PM CDT 4.7 10.00 Clear -- 65.1 64.9 99% NA NA 29.82 1009.8

Regional Weather Observation

SPARTA (KSAR)

Clear
65.1 F

CAHOKIA/ST LOUIS (KCPS)

Clear
44.6 F

PERRYVILLE (KPCD)

Clear
50.9 F

SCOTT AFB/BELLEV (KBLV)

Clear
44.4 F

FARMINGTON (KFAM)

Clear
46.4 F

ST LOUIS (KSTL)

Clear
44.6 F
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