Weather World
City of Ottawa, ILOttawa, IL 7-Day Weather Forecast
Quick Weather Clicks
Settings
Sun & Moon
Ottawa Weather Forecast
Ottawa, IL Weather Forecast Date: 705 PM CDT Thu Sep 17 2026
Weather forecast for Ottawa, IL
Tonight Lo: 65°F Lo: 18°C |
Tonight... Mostly cloudy. A slight chance of showers and thunderstorms in the evening. A slight chance of showers late. Lows in the mid 60s. Northeast winds 5 to 10 mph. Chance of precipitation 20%. |
Fri Hi: 75°FHi: 24°C Lo: 65°F Lo: 18°C |
Friday... Mostly cloudy. A slight chance of showers in the late morning and afternoon. A slight chance of thunderstorms late. Highs in the mid 70s. East winds 5 to 10 mph. Chance of precipitation 20%. |
| Sat Hi: 80°FHi: 27°C Lo: 65°F Lo: 18°C |
Saturday... Showers with a slight chance of thunderstorms. Humid with highs around 80. South winds 5 to 10 mph. Chance of precipitation 80%. |
| Sun Hi: 71°FHi: 22°C Lo: 59°F Lo: 15°C |
Sunday... Mostly cloudy with a slight chance of thunderstorms. Showers likely, mainly in the morning. Highs in the lower 70s. Chance of precipitation 70%. |
| Mon Hi: 65°FHi: 18°C Lo: 55°F Lo: 13°C |
Monday... Mostly cloudy with a slight chance of thunderstorms. Showers likely, mainly in the morning. Highs in the mid 60s. Chance of precipitation 60%. |
Tue Hi: 65°FHi: 18°C Lo: 51°F Lo: 11°C |
Tuesday... Mostly cloudy. A chance of showers in the morning. Highs in the mid 60s. Chance of precipitation 30%. |
Wed Hi: 70°FHi: 21°C Lo: 55°F Lo: 13°C |
Wednesday... Partly cloudy in the morning, then becoming mostly cloudy. Highs around 70. |
Ottawa Radar Loop
Use the map search tool if you want to place a location marker on the radar map...