Washington County, IL Weather Forecast
County weather hub
Slight Chance Showers And Thunderstorms then Mostly Sunny
Compare major city weather across Washington County, scan the latest forecast snapshots, and jump into local 7-day outlook pages from one hub.
A slight chance of showers and thunderstorms between 8am and noon. Mostly sunny, with a high near 83. South wind 6 to 16 mph. Chance of precipitation is 20%.
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
- Apr 17 to Apr 22, 2026
- Latest sync
- Apr 16, 2026 7:41 PM CDT
- Forecast office
- LSX
- Source
- NOAA / NWS
Daily Outlook
This Week in Washington County
Friday looks like the warmest upcoming period in Washington County at 83 degrees F.
Saturday Night is the coolest period ahead with temperatures near 38 degrees F.
The strongest winds are forecast for Saturday at about 15 to 18 mph W.
Precipitation is mentioned in 4 upcoming forecast periods.
Forecast Details
- Last updated
- Apr 16, 2026 7:41 PM CDT
- Coverage
- 6 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
A chance of showers and thunderstorms between 10pm and midnight, then showers and thunderstorms. Mostly cloudy. Low around 52, with temperatures rising to around 61 overnight. Southwest wind around 15 mph, with gusts as high as 23 mph. Chance of precipitation is 100%.
Showers and thunderstorms. Partly sunny. High near 62, with temperatures falling to around 57 in the afternoon. West wind 15 to 18 mph. Chance of precipitation is 80%.
A chance of rain showers before 7pm. Mostly clear, with a low around 38. Chance of precipitation is 40%.
Sunny, with a high near 64.
Mostly clear, with a low around 41.
Sunny, with a high near 70.
Mostly clear, with a low around 52.
Sunny, with a high near 76.
Partly cloudy, with a low around 56.
Mostly sunny, with a high near 76.
Mostly clear, with a low around 56.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Friday
Apr 17
|
Slight Chance Showers And Thunderstorms then Mostly Sunny
|
83°F |
6 to 16 mph
S
|
|
Friday Night
Apr 17
|
Chance Showers And Thunderstorms then Showers And Thunderstorms
|
52°F |
15 mph
SW
|
|
Saturday
Apr 18
|
Showers And Thunderstorms
|
62°F |
15 to 18 mph
W
|
|
Saturday Night
Apr 18
|
Chance Rain Showers then Mostly Clear
|
38°F |
6 to 15 mph
NW
|
|
Sunday
Apr 19
|
Sunny
|
64°F |
6 to 14 mph
NW
|
|
Sunday Night
Apr 19
|
Mostly Clear
|
41°F |
3 to 8 mph
NE
|
|
Monday
Apr 20
|
Sunny
|
70°F |
5 to 8 mph
SE
|
|
Monday Night
Apr 20
|
Mostly Clear
|
52°F |
9 mph
S
|
|
Tuesday
Apr 21
|
Sunny
|
76°F |
9 to 15 mph
SW
|
|
Tuesday Night
Apr 21
|
Partly Cloudy
|
56°F |
8 to 12 mph
SW
|
|
Wednesday
Apr 22
|
Mostly Sunny
|
76°F |
7 to 10 mph
SW
|
|
Wednesday Night
Apr 22
|
Mostly Clear
|
56°F |
8 mph
S
|
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.
