Johnson County, IL Weather Forecast
County weather hub
Showers And Thunderstorms Likely
Compare major city weather across Johnson County, scan the latest forecast snapshots, and jump into local 7-day outlook pages from one hub.
Showers and thunderstorms likely before 4pm, then a chance of showers and thunderstorms. Mostly sunny, with a high near 85. North northeast wind 0 to 3 mph. Chance of precipitation is 60%.
County Weather Overview
This county weather page brings together forecast coverage for Johnson County so visitors can compare temperatures, wind, and conditions across the region without hopping between unrelated pages.
Current forecast coverage spans 3 of 3 mapped cities in Johnson County.
Page Snapshot
- Page focus
- county weather
- Forecast window
- Jun 1 to Jun 5, 2026
- Latest sync
- May 30, 2026 10:31 AM CDT
- Forecast office
- PAH
- Source
- NOAA / NWS
Daily Outlook
This Week in Johnson County
Monday looks like the warmest upcoming period in Johnson County at 85 degrees F.
Tuesday Night is the coolest period ahead with temperatures near 58 degrees F.
The strongest winds are forecast for Friday at about 2 to 9 mph SSW.
Precipitation is mentioned in 5 upcoming forecast periods.
Forecast Details
- Last updated
- May 30, 2026 10:31 AM CDT
- Coverage
- 5 days
- Time zone
- America/Chicago
- Forecast office
- PAH
- Radar station
- KPAH
Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.
Open NOAA sourceExtended Forecast
A chance of showers and thunderstorms before 1am. Mostly clear, with a low around 63. North northeast wind around 2 mph. Chance of precipitation is 40%.
Sunny, with a high near 82. Northeast wind 1 to 8 mph.
Clear, with a low around 58. Northeast wind 1 to 6 mph.
Sunny, with a high near 81. East northeast wind 2 to 6 mph.
Clear, with a low around 59. East northeast wind 0 to 5 mph.
Sunny, with a high near 83. South southeast wind 0 to 6 mph.
A slight chance of showers and thunderstorms between 7pm and 1am. Partly cloudy, with a low around 64. South wind around 3 mph.
A chance of showers and thunderstorms after 7am. Mostly sunny, with a high near 85. South southwest wind 2 to 9 mph.
A chance of showers and thunderstorms. Partly cloudy, with a low around 69. South southwest wind 2 to 7 mph.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Monday
Jun 1
|
Showers And Thunderstorms Likely
|
85°F |
0 to 3 mph
NNE
|
|
Monday Night
Jun 1
|
Chance Showers And Thunderstorms
|
63°F |
2 mph
NNE
|
|
Tuesday
Jun 2
|
Sunny
|
82°F |
1 to 8 mph
NE
|
|
Tuesday Night
Jun 2
|
Clear
|
58°F |
1 to 6 mph
NE
|
|
Wednesday
Jun 3
|
Sunny
|
81°F |
2 to 6 mph
ENE
|
|
Wednesday Night
Jun 3
|
Clear
|
59°F |
0 to 5 mph
ENE
|
|
Thursday
Jun 4
|
Sunny
|
83°F |
0 to 6 mph
SSE
|
|
Thursday Night
Jun 4
|
Slight Chance Showers And Thunderstorms
|
64°F |
3 mph
S
|
|
Friday
Jun 5
|
Chance Showers And Thunderstorms
|
85°F |
2 to 9 mph
SSW
|
|
Friday Night
Jun 5
|
Chance Showers And Thunderstorms
|
69°F |
2 to 7 mph
SSW
|
Major City Forecasts
Live forecast snapshots for major cities across Johnson County.
Coverage
Forecast coverage currently spans 3 of 3 mapped cities in Johnson County.
Largest mapped city population in this region: 1,427.
