Johnson County, IL Weather Forecast
County weather hub
Partly Sunny then Chance Showers And Thunderstorms
Compare major city weather across Johnson County, scan the latest forecast snapshots, and jump into local 7-day outlook pages from one hub.
A chance of showers and thunderstorms after noon. Partly sunny. High near 87, with temperatures falling to around 85 in the afternoon. Southwest wind around 3 mph. Chance of precipitation is 40%.
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
- Jul 16 to Jul 22, 2026
- Latest sync
- Jul 16, 2026 1:13 PM CDT
- Forecast office
- PAH
- Source
- NOAA / NWS
Daily Outlook
This Week in Johnson County
Tuesday looks like the warmest upcoming period in Johnson County at 92 degrees F.
Wednesday Night is the coolest period ahead with temperatures near 67 degrees F.
The strongest winds are forecast for Wednesday at about 3 to 8 mph NNE.
Precipitation is mentioned in 10 upcoming forecast periods.
Forecast Details
- Last updated
- Jul 16, 2026 1:13 PM CDT
- Coverage
- 7 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 7pm. Partly cloudy. Low around 72, with temperatures rising to around 74 overnight. West northwest wind around 1 mph. Chance of precipitation is 30%.
A chance of showers and thunderstorms after 11am. Mostly sunny. High near 89, with temperatures falling to around 86 in the afternoon. West northwest wind 0 to 5 mph. Chance of precipitation is 50%.
A slight chance of showers and thunderstorms before 7pm. Mostly clear, with a low around 73. West wind around 2 mph. Chance of precipitation is 20%.
A chance of showers and thunderstorms after 1pm. Sunny, with a high near 91. West wind 1 to 7 mph. Chance of precipitation is 40%.
A chance of showers and thunderstorms before 10pm, then a chance of showers and thunderstorms between 10pm and 1am. Partly cloudy, with a low around 73. West wind 0 to 3 mph. Chance of precipitation is 40%.
A slight chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 90. Northwest wind around 3 mph.
A slight chance of showers and thunderstorms before 7pm. Mostly clear, with a low around 70. North wind around 2 mph.
Mostly sunny, with a high near 91. West southwest wind 0 to 3 mph.
Partly cloudy, with a low around 74. Southwest wind around 2 mph.
A slight chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92. West northwest wind 2 to 7 mph.
A slight chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 71. North wind 2 to 6 mph.
Mostly sunny, with a high near 87. North northeast wind 3 to 8 mph.
Partly cloudy, with a low around 67. Northeast wind 1 to 5 mph.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Today
Jul 16
|
Partly Sunny then Chance Showers And Thunderstorms
|
87°F |
3 mph
SW
|
|
Tonight
Jul 16
|
Chance Showers And Thunderstorms then Partly Cloudy
|
72°F |
1 mph
WNW
|
|
Friday
Jul 17
|
Chance Showers And Thunderstorms
|
89°F |
0 to 5 mph
WNW
|
|
Friday Night
Jul 17
|
Slight Chance Showers And Thunderstorms then Mostly Clear
|
73°F |
2 mph
W
|
|
Saturday
Jul 18
|
Sunny then Chance Showers And Thunderstorms
|
91°F |
1 to 7 mph
W
|
|
Saturday Night
Jul 18
|
Chance Showers And Thunderstorms
|
73°F |
0 to 3 mph
W
|
|
Sunday
Jul 19
|
Mostly Sunny then Slight Chance Showers And Thunderstorms
|
90°F |
3 mph
NW
|
|
Sunday Night
Jul 19
|
Slight Chance Showers And Thunderstorms then Mostly Clear
|
70°F |
2 mph
N
|
|
Monday
Jul 20
|
Mostly Sunny
|
91°F |
0 to 3 mph
WSW
|
|
Monday Night
Jul 20
|
Partly Cloudy
|
74°F |
2 mph
SW
|
|
Tuesday
Jul 21
|
Mostly Sunny then Slight Chance Showers And Thunderstorms
|
92°F |
2 to 7 mph
WNW
|
|
Tuesday Night
Jul 21
|
Slight Chance Showers And Thunderstorms
|
71°F |
2 to 6 mph
N
|
|
Wednesday
Jul 22
|
Mostly Sunny
|
87°F |
3 to 8 mph
NNE
|
|
Wednesday Night
Jul 22
|
Partly Cloudy
|
67°F |
1 to 5 mph
NE
|
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.
