Grand Detour, IL Weather Forecast
Local 7-day forecast
Mostly Sunny
Track current conditions, temperature changes, wind, and the full daily outlook for Grand Detour, IL in one place.
Mostly sunny, with a high near 78. West northwest wind 0 to 5 mph.
Local Weather Overview
This forecast page for Grand Detour, IL is designed for quick trip planning, giving you a clean read on daytime highs, overnight lows, and changing conditions across the upcoming forecast window. Latest sync: Aug 23, 2026 2:57 AM CDT.
The active forecast window currently covers Aug 24 to Aug 29, 2026 for Grand Detour, IL.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Aug 24 to Aug 29, 2026
- Latest sync
- Aug 23, 2026 2:57 AM CDT
- Forecast office
- LOT
- Source
- NOAA / NWS
Daily Outlook
This Week in Grand Detour
Wednesday looks like the warmest upcoming period in Grand Detour at 83 degrees F.
Monday Night is the coolest period ahead with temperatures near 57 degrees F.
The strongest winds are forecast for Wednesday at about 5 to 10 mph SW.
Precipitation is mentioned in 4 upcoming forecast periods.
Forecast Details
- Last updated
- Aug 23, 2026 2:57 AM CDT
- Coverage
- 6 days
- Time zone
- America/Chicago
- Forecast office
- LOT
- 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 57. East wind 0 to 5 mph.
Mostly sunny, with a high near 80.
A slight chance of rain showers between 7pm and 1am, then a slight chance of showers and thunderstorms. Partly cloudy, with a low around 62.
A slight chance of showers and thunderstorms before 1pm, then a chance of showers and thunderstorms. Mostly sunny, with a high near 83.
A chance of showers and thunderstorms before 7pm, then a slight chance of showers and thunderstorms between 7pm and 1am. Partly cloudy, with a low around 62.
Sunny, with a high near 81.
Mostly clear, with a low around 60.
Sunny, with a high near 80.
Partly cloudy, with a low around 60.
A slight chance of showers and thunderstorms after 7am. Mostly sunny, with a high near 80.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Monday
Aug 24
|
Mostly Sunny
|
78°F |
0 to 5 mph
WNW
|
|
Monday Night
Aug 24
|
Partly Cloudy
|
57°F |
0 to 5 mph
E
|
|
Tuesday
Aug 25
|
Mostly Sunny
|
80°F |
0 to 5 mph
S
|
|
Tuesday Night
Aug 25
|
Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms
|
62°F |
5 mph
SSW
|
|
Wednesday
Aug 26
|
Slight Chance Showers And Thunderstorms
|
83°F |
5 to 10 mph
SW
|
|
Wednesday Night
Aug 26
|
Chance Showers And Thunderstorms then Slight Chance Showers And Thunderstorms
|
62°F |
5 to 10 mph
W
|
|
Thursday
Aug 27
|
Sunny
|
81°F |
5 to 10 mph
NW
|
|
Thursday Night
Aug 27
|
Mostly Clear
|
60°F |
0 to 5 mph
NNW
|
|
Friday
Aug 28
|
Sunny
|
80°F |
0 to 5 mph
NNW
|
|
Friday Night
Aug 28
|
Partly Cloudy
|
60°F |
0 mph
|
|
Saturday
Aug 29
|
Slight Chance Showers And Thunderstorms
|
80°F |
0 to 5 mph
SSE
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around Grand Detour.
