Ottawa, IL Weather Forecast
Local 7-day forecast
Partly Sunny
Track current conditions, temperature changes, wind, and the full daily outlook for Ottawa, IL in one place.
Partly sunny, with a high near 82. South wind 5 to 10 mph, with gusts as high as 20 mph.
Local Weather Overview
This forecast page for Ottawa, 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 27, 2026 6:35 PM CDT.
The active forecast window currently covers Aug 29 to Sep 2, 2026 for Ottawa, IL.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Aug 29 to Sep 2, 2026
- Latest sync
- Aug 27, 2026 6:35 PM CDT
- Forecast office
- LOT
- Source
- NOAA / NWS
Daily Outlook
This Week in Ottawa
Monday looks like the warmest upcoming period in Ottawa at 90 degrees F.
Saturday Night is the coolest period ahead with temperatures near 68 degrees F.
The strongest winds are forecast for Sunday at about 10 to 15 mph S.
Precipitation is mentioned in 6 upcoming forecast periods.
Forecast Details
- Last updated
- Aug 27, 2026 6:35 PM CDT
- Coverage
- 5 days
- Time zone
- America/Chicago
- Forecast office
- LOT
- Radar station
- KLOT
Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.
Open NOAA sourceExtended Forecast
A slight chance of rain showers between 7pm and 1am. Mostly cloudy, with a low around 68. Chance of precipitation is 20%.
Mostly sunny, with a high near 88.
Partly cloudy, with a low around 73.
Mostly sunny, with a high near 90.
A slight chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 74.
A slight chance of showers and thunderstorms before 1pm. Mostly sunny, with a high near 90.
A slight chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 72.
A slight chance of showers and thunderstorms before 1pm. Mostly sunny, with a high near 90.
A slight chance of showers and thunderstorms after 1am. Mostly clear, with a low around 71.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Saturday
Aug 29
|
Partly Sunny
|
82°F |
5 to 10 mph
S
|
|
Saturday Night
Aug 29
|
Slight Chance Rain Showers
|
68°F |
5 to 10 mph
SSE
|
|
Sunday
Aug 30
|
Mostly Sunny
|
88°F |
10 to 15 mph
S
|
|
Sunday Night
Aug 30
|
Partly Cloudy
|
73°F |
10 mph
S
|
|
Monday
Aug 31
|
Mostly Sunny
|
90°F |
5 to 10 mph
SSW
|
|
Monday Night
Aug 31
|
Partly Cloudy then Slight Chance Showers And Thunderstorms
|
74°F |
5 mph
SSW
|
|
Tuesday
Sep 1
|
Slight Chance Showers And Thunderstorms
|
90°F |
5 mph
SW
|
|
Tuesday Night
Sep 1
|
Partly Cloudy then Slight Chance Showers And Thunderstorms
|
72°F |
0 to 5 mph
SSW
|
|
Wednesday
Sep 2
|
Slight Chance Showers And Thunderstorms
|
90°F |
0 to 5 mph
SW
|
|
Wednesday Night
Sep 2
|
Mostly Clear then Slight Chance Showers And Thunderstorms
|
71°F |
0 to 5 mph
SSE
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around Ottawa.
