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. Mostly cloudy. Low around 63, with temperatures rising to around 65 overnight. Southwest wind around 6 mph. Chance of precipitation is 70%.
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
- Apr 16 to Apr 22, 2026
- Latest sync
- Apr 16, 2026 5:19 AM CDT
- Forecast office
- PAH
- Source
- NOAA / NWS
Daily Outlook
This Week in Johnson County
Friday looks like the warmest upcoming period in Johnson County at 85 degrees F.
Saturday Night is the coolest period ahead with temperatures near 41 degrees F.
The strongest winds are forecast for Saturday at about 9 to 13 mph WNW.
Precipitation is mentioned in 8 upcoming forecast periods.
Forecast Details
- Last updated
- Apr 16, 2026 5:19 AM 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
Showers and thunderstorms likely before 4pm, then a chance of showers and thunderstorms. Partly sunny, with a high near 80. Southwest wind 5 to 9 mph. Chance of precipitation is 70%.
A chance of showers and thunderstorms before 7pm. Mostly clear. Low around 59, with temperatures rising to around 61 overnight. South southwest wind 1 to 6 mph. Chance of precipitation is 30%.
A chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 85. South wind 2 to 10 mph, with gusts as high as 21 mph. Chance of precipitation is 40%.
A chance of showers and thunderstorms before 1am, then showers and thunderstorms likely. Mostly cloudy, with a low around 56. South southwest wind around 9 mph, with gusts as high as 20 mph. Chance of precipitation is 60%.
Showers and thunderstorms. Mostly cloudy, with a high near 70. West northwest wind 9 to 13 mph, with gusts as high as 23 mph. Chance of precipitation is 80%.
Rain showers likely before 1am. Partly cloudy, with a low around 41. Northwest wind 2 to 9 mph, with gusts as high as 20 mph.
Sunny, with a high near 67. Northwest wind 2 to 9 mph, with gusts as high as 18 mph.
Clear, with a low around 42. Northeast wind around 5 mph.
Sunny, with a high near 72. South southeast wind 2 to 7 mph.
Mostly clear, with a low around 50. South wind around 5 mph.
Mostly sunny, with a high near 77. South southwest wind 2 to 10 mph, with gusts as high as 21 mph.
Partly cloudy, with a low around 54. South southwest wind 3 to 7 mph.
A slight chance of rain showers between 7am and 1pm, then a slight chance of showers and thunderstorms. Mostly sunny, with a high near 79. Southwest wind 3 to 9 mph, with gusts as high as 20 mph.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Overnight
Apr 16
|
Showers And Thunderstorms Likely
|
63°F |
6 mph
SW
|
|
Thursday
Apr 16
|
Showers And Thunderstorms Likely
|
80°F |
5 to 9 mph
SW
|
|
Thursday Night
Apr 16
|
Chance Showers And Thunderstorms then Mostly Clear
|
59°F |
1 to 6 mph
SSW
|
|
Friday
Apr 17
|
Mostly Sunny then Chance Showers And Thunderstorms
|
85°F |
2 to 10 mph
S
|
|
Friday Night
Apr 17
|
Chance Showers And Thunderstorms
|
56°F |
9 mph
SSW
|
|
Saturday
Apr 18
|
Showers And Thunderstorms
|
70°F |
9 to 13 mph
WNW
|
|
Saturday Night
Apr 18
|
Rain Showers Likely
|
41°F |
2 to 9 mph
NW
|
|
Sunday
Apr 19
|
Sunny
|
67°F |
2 to 9 mph
NW
|
|
Sunday Night
Apr 19
|
Clear
|
42°F |
5 mph
NE
|
|
Monday
Apr 20
|
Sunny
|
72°F |
2 to 7 mph
SSE
|
|
Monday Night
Apr 20
|
Mostly Clear
|
50°F |
5 mph
S
|
|
Tuesday
Apr 21
|
Mostly Sunny
|
77°F |
2 to 10 mph
SSW
|
|
Tuesday Night
Apr 21
|
Partly Cloudy
|
54°F |
3 to 7 mph
SSW
|
|
Wednesday
Apr 22
|
Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms
|
79°F |
3 to 9 mph
SW
|
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.
