Johnson County, IL Weather Forecast
County weather hub
Sunny
Compare major city weather across Johnson County, scan the latest forecast snapshots, and jump into local 7-day outlook pages from one hub.
Sunny, with a high near 77. North northeast wind around 1 mph.
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
- Oct 21 to Oct 25, 2026
- Latest sync
- Oct 18, 2026 10:38 PM CDT
- Forecast office
- PAH
- Source
- NOAA / NWS
Daily Outlook
This Week in Johnson County
Sunday looks like the warmest upcoming period in Johnson County at 79 degrees F.
Wednesday Night is the coolest period ahead with temperatures near 45 degrees F.
The strongest winds are forecast for Friday at about 0 to 5 mph ENE.
The forecast from Oct 21 through Oct 25 stays mostly dry.
Forecast Details
- Last updated
- Oct 18, 2026 10:38 PM 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
Clear, with a low around 45. Wind around 0 mph.
Sunny, with a high near 76. North northeast wind around 2 mph.
Clear, with a low around 47. North northeast wind around 1 mph.
Sunny, with a high near 76. East northeast wind 0 to 5 mph.
Mostly clear, with a low around 46. East wind around 3 mph.
Sunny, with a high near 78. Southeast wind 1 to 5 mph.
Partly cloudy, with a low around 49. East northeast wind around 1 mph.
Mostly sunny, with a high near 79. Southwest wind 0 to 3 mph.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Wednesday
Oct 21
|
Sunny
|
77°F |
1 mph
NNE
|
|
Wednesday Night
Oct 21
|
Clear
|
45°F |
0 mph
|
|
Thursday
Oct 22
|
Sunny
|
76°F |
2 mph
NNE
|
|
Thursday Night
Oct 22
|
Clear
|
47°F |
1 mph
NNE
|
|
Friday
Oct 23
|
Sunny
|
76°F |
0 to 5 mph
ENE
|
|
Friday Night
Oct 23
|
Mostly Clear
|
46°F |
3 mph
E
|
|
Saturday
Oct 24
|
Sunny
|
78°F |
1 to 5 mph
SE
|
|
Saturday Night
Oct 24
|
Partly Cloudy
|
49°F |
1 mph
ENE
|
|
Sunday
Oct 25
|
Mostly Sunny
|
79°F |
0 to 3 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.
