Mercer County, IL Weather Forecast
County weather hub
Showers And Thunderstorms Likely
Compare major city weather across Mercer County, scan the latest forecast snapshots, and jump into local 7-day outlook pages from one hub.
Showers and thunderstorms likely before 2pm. Some of the storms could be severe. Mostly sunny, with a high near 90. Heat index values as high as 102. Southwest wind 5 to 10 mph. Chance of precipitation is 60%.
County Weather Overview
This county weather page brings together forecast coverage for Mercer 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 Mercer County.
Page Snapshot
- Page focus
- county weather
- Forecast window
- Aug 11 to Aug 17, 2026
- Latest sync
- Aug 11, 2026 12:51 PM CDT
- Forecast office
- DVN
- Source
- NOAA / NWS
Daily Outlook
This Week in Mercer County
Today looks like the warmest upcoming period in Mercer County at 90 degrees F.
Monday Night is the coolest period ahead with temperatures near 64 degrees F.
The strongest winds are forecast for Friday Night at about 10 to 15 mph E.
Precipitation is mentioned in 13 upcoming forecast periods.
Forecast Details
- Last updated
- Aug 11, 2026 12:51 PM CDT
- Coverage
- 7 days
- Time zone
- America/Chicago
- Forecast office
- DVN
- Radar station
- KDVN
Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.
Open NOAA sourceExtended Forecast
Partly cloudy, with a low around 71. Northeast wind 0 to 5 mph.
Showers and thunderstorms likely before 5pm. Partly sunny, with a high near 87. Southeast wind around 5 mph. Chance of precipitation is 60%.
A slight chance of rain showers before 7pm, then a chance of showers and thunderstorms between 7pm and 1am, then showers and thunderstorms likely. Partly cloudy, with a low around 70. Northeast wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Showers and thunderstorms. Mostly cloudy, with a high near 82. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.
Showers and thunderstorms before 7pm, then a chance of showers and thunderstorms between 7pm and 1am, then showers and thunderstorms likely. Mostly cloudy, with a low around 67. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
Showers and thunderstorms likely before 1pm, then a slight chance of showers and thunderstorms. Mostly cloudy, with a high near 80. Chance of precipitation is 70%.
A slight chance of showers and thunderstorms before 7pm, then showers and thunderstorms likely. Mostly cloudy, with a low around 67. Chance of precipitation is 60%.
Showers and thunderstorms likely before 7am, then a chance of showers and thunderstorms between 7am and 1pm. Partly sunny, with a high near 86. Chance of precipitation is 60%.
A chance of showers and thunderstorms after 7pm. Partly cloudy, with a low around 71. Chance of precipitation is 50%.
A chance of showers and thunderstorms before 1pm. Partly sunny, with a high near 83. Chance of precipitation is 50%.
A slight chance of rain showers after 7pm. Mostly cloudy, with a low around 66.
A slight chance of rain showers before 7am. Mostly sunny, with a high near 79.
A slight chance of rain showers after 1am. Partly cloudy, with a low around 64.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Today
Aug 11
|
Showers And Thunderstorms Likely
|
90°F |
5 to 10 mph
SW
|
|
Tonight
Aug 11
|
Partly Cloudy
|
71°F |
0 to 5 mph
NE
|
|
Wednesday
Aug 12
|
Showers And Thunderstorms Likely
|
87°F |
5 mph
SE
|
|
Wednesday Night
Aug 12
|
Chance Showers And Thunderstorms
|
70°F |
5 mph
NE
|
|
Thursday
Aug 13
|
Showers And Thunderstorms
|
82°F |
5 mph
NE
|
|
Thursday Night
Aug 13
|
Showers And Thunderstorms then Chance Showers And Thunderstorms
|
67°F |
5 to 10 mph
NE
|
|
Friday
Aug 14
|
Showers And Thunderstorms Likely
|
80°F |
10 mph
E
|
|
Friday Night
Aug 14
|
Slight Chance Showers And Thunderstorms then Showers And Thunderstorms Likely
|
67°F |
10 to 15 mph
E
|
|
Saturday
Aug 15
|
Showers And Thunderstorms Likely then Chance Showers And Thunderstorms
|
86°F |
10 mph
SE
|
|
Saturday Night
Aug 15
|
Chance Showers And Thunderstorms
|
71°F |
5 to 10 mph
S
|
|
Sunday
Aug 16
|
Chance Showers And Thunderstorms
|
83°F |
5 to 10 mph
W
|
|
Sunday Night
Aug 16
|
Slight Chance Rain Showers
|
66°F |
5 mph
N
|
|
Monday
Aug 17
|
Slight Chance Rain Showers then Mostly Sunny
|
79°F |
5 mph
N
|
|
Monday Night
Aug 17
|
Partly Cloudy then Slight Chance Rain Showers
|
64°F |
0 to 5 mph
NE
|
Major City Forecasts
Live forecast snapshots for major cities across Mercer County.
Coverage
Forecast coverage currently spans 2 of 2 mapped cities in Mercer County.
Largest mapped city population in this region: 3,383.
