Johnstown, Illinois Weather
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Weather Forecast for Johnstown, Illinois : Cumberland County
Issued: 12:42 pm CDT Jun 2, 2025 Latitude: 39.3633698 Longitude: -88.2869878 View on Google Maps

MouseOver for Detail Forecast
This Afternoon Tonight Tuesday Wednesday Thursday Friday Saturday Sunday
Mostly Sunny on This Afternoon Cloudy on Tonight Mostly Sunny on Tuesday 80% chance of thunderstorms on Wednesday 70% chance of thunderstorms on Thursday 50% chance of thunderstorms on Friday 20% chance of on Saturday 20% chance of rain on Sunday
High: 84°F Low: 63°F High: 88°F High: 84°F High: 80°F High: 79°F High: 78°F High: 79°F
Low: 70°F Low: 66°F Low: 65°F Low: 62°F Low: 61°F  
Mostly Sunny Cloudy Mostly Sunny Thunderstorms Thunderstorms Thunderstorms Partly Sunny Rain
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Current Conditions at
MATTOON - (KMTO)
79°
Clear
as of 12:53 PM CDST
Rel. Humidity: 31%
Dew Point: 46°F
Visibility: 10 Miles
Pressure: 30.02 in.
Flight Rule: VFR
Wind Data
10 MPH
Gust: 24 MPH
170° South
Cloud Level(s): Clear
Current Conditions at
EFFINGHAM COUNTY MEMORIAL - (K1H2)
81°
Clear
as of 1:15 PM CDST
Rel. Humidity: 30%
Dew Point: 46°F
Visibility: 10 Miles
Pressure: 30.03 in.
Flight Rule: VFR
Wind Data
12 MPH
120° Southeast
Cloud Level(s): Clear
Current Conditions at
EDGAR COUNTY ARPT - (KPRG)
81°
Clear
as of 1:15 PM CDST
Rel. Humidity: 28%
Dew Point: 45°F
Visibility: 10 Miles
Pressure: 30.02 in.
Flight Rule: VFR
Wind Data
13 MPH
Gust: 16 MPH
170° South
Cloud Level(s): Clear
Current Conditions at
DECATUR - (KDEC)
82°
Clear
as of 12:54 PM CDST
Rel. Humidity: 30%
Dew Point: 48°F
Visibility: 10 Miles
Pressure: 30.00 in.
Flight Rule: VFR
Wind Data
14 MPH
Gust: 20 MPH
160° South
Cloud Level(s): Clear
Mostly Sunny on This Afternoon This Afternoon... Mostly sunny, with a high near 84. South wind around 9 mph.
Cloudy on Tonight Tonight... Partly cloudy, with a low around 63. South southeast wind around 7 mph, with gusts as high as 15 mph.
Mostly Sunny on Tuesday Tuesday... Mostly sunny, with a high near 88. Breezy, with a south southwest wind 9 to 14 mph increasing to 15 to 20 mph in the afternoon. Winds could gust as high as 31 mph.
Mostly Cloudy on Tuesday Night Tuesday Night... Mostly cloudy, with a low around 70. South wind 10 to 15 mph, with gusts as high as 25 mph.
80% chance of thunderstorms Wednesday Wednesday... A chance of showers, then showers and possibly a thunderstorm after 1pm. High near 84. South southwest wind 10 to 13 mph, with gusts as high as 22 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
70% chance of thunderstorms Wednesday Night Wednesday Night... Showers likely and possibly a thunderstorm. Cloudy, with a low around 66. South wind around 6 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
70% chance of thunderstorms Thursday Thursday... Showers likely, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 80. Southwest wind around 7 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
60% chance of thunderstorms Thursday Night Thursday Night... Showers likely and possibly a thunderstorm before 1am, then a chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 65. Chance of precipitation is 60%.
50% chance of thunderstorms Friday Friday... A chance of showers, with thunderstorms also possible after 1pm. Partly sunny, with a high near 79. Chance of precipitation is 50%.
30% chance of thunderstorms Friday Night Friday Night... A chance of showers and thunderstorms. Partly cloudy, with a low around 62. Chance of precipitation is 30%.
20% chance of Saturday Saturday... A chance of showers. Partly sunny, with a high near 78.
20% chance of rain Saturday Night Saturday Night... A chance of showers. Partly cloudy, with a low around 61.
20% chance of rain Sunday Sunday... A chance of showers. Mostly cloudy, with a high near 79.
Current Radar Image


Sun Almanac for Johnstown, Illinois
Sunrise: 05:28 AM
Sunset: 8:15 PM
Civil Sunrise:04:56 AM
Civil Sunset: 8:47 PM
Nautical Sunrise: 04:16 AM
Nautical Sunset: 9:27 PM
Astro Sunrise: 03:30 AM
Astro Sunset: 10:12 PM
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