Washington County, IL Weather Forecast
County weather hub
Sunny
Compare major city weather across Washington County, scan the latest forecast snapshots, and jump into local 7-day outlook pages from one hub.
Sunny, with a high near 59. North wind 2 to 8 mph.
County Weather Overview
This county weather page brings together forecast coverage for Washington County so visitors can compare temperatures, wind, and conditions across the region without hopping between unrelated pages.
Current forecast coverage spans 2 of 2 mapped cities in Washington County.
Page Snapshot
- Page focus
- county weather
- Forecast window
- Oct 17 to Oct 21, 2026
- Latest sync
- Oct 15, 2026 4:51 PM CDT
- Forecast office
- LSX
- Source
- NOAA / NWS
Daily Outlook
This Week in Washington County
Wednesday looks like the warmest upcoming period in Washington County at 78 degrees F.
Saturday Night is the coolest period ahead with temperatures near 35 degrees F.
The strongest winds are forecast for Saturday at about 2 to 8 mph N.
The forecast from Oct 17 through Oct 21 stays mostly dry.
Forecast Details
- Last updated
- Oct 15, 2026 4:51 PM CDT
- Coverage
- 5 days
- Time zone
- America/Chicago
- Forecast office
- LSX
- Radar station
- KLSX
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 35.
Sunny, with a high near 66.
Mostly clear, with a low around 38.
Sunny, with a high near 71.
Partly cloudy, with a low around 43.
Mostly sunny, with a high near 76.
Mostly clear, with a low around 45.
Sunny, with a high near 78.
Mostly clear, with a low around 47.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Saturday
Oct 17
|
Sunny
|
59°F |
2 to 8 mph
N
|
|
Saturday Night
Oct 17
|
Clear
|
35°F |
2 mph
E
|
|
Sunday
Oct 18
|
Sunny
|
66°F |
2 to 6 mph
SE
|
|
Sunday Night
Oct 18
|
Mostly Clear
|
38°F |
3 mph
SE
|
|
Monday
Oct 19
|
Sunny
|
71°F |
1 to 5 mph
S
|
|
Monday Night
Oct 19
|
Partly Cloudy
|
43°F |
1 mph
SE
|
|
Tuesday
Oct 20
|
Mostly Sunny
|
76°F |
0 to 3 mph
E
|
|
Tuesday Night
Oct 20
|
Mostly Clear
|
45°F |
2 mph
E
|
|
Wednesday
Oct 21
|
Sunny
|
78°F |
0 to 3 mph
E
|
|
Wednesday Night
Oct 21
|
Mostly Clear
|
47°F |
2 mph
E
|
Major City Forecasts
Live forecast snapshots for major cities across Washington County.
Coverage
Forecast coverage currently spans 2 of 2 mapped cities in Washington County.
Largest mapped city population in this region: 2,984.
