RECMKX Recreational Boater Forecast for Inland Lakes for Southeast Wisconsin National Weather Service Milwaukee/Sullivan WI 1532 CDT Thu Apr 23 2026 ...Lake Koshkonong... .TONIGHT... Waves...............1.5 to 2 feet. Sky/Weather.........Mostly sunny until 8 PM, then mostly cloudy. Numerous showers and chance of thunderstorms after 8 PM. Min Temperature.....Around 59. Winds...............South winds 10 to 15 mph. Water Temperature...62 degrees. UV Index............6 - High. .FRIDAY... Waves...............Half foot to 1 foot. Sky/Weather.........Mostly cloudy until 2 PM, then sunny. Chance of showers and slight chance of thunderstorms. Slight chance of showers after 2 PM until 5 PM. Max Temperature.....Around 68. Winds...............West winds around 10 mph. Water Temperature...62 degrees. UV Index............6 - High. .FRIDAY NIGHT... Waves...............Half foot to 1 foot. Sky/Weather.........Mostly clear. Min Temperature.....Mid 40s. Winds...............North winds around 5 mph. .SATURDAY... Waves...............Half foot to 1 foot. Sky/Weather.........Sunny. Max Temperature.....Upper 60s. Winds...............Northeast winds 5 to 10 mph. .SUNDAY... Waves...............1 to 1.5 feet. Sky/Weather.........Partly sunny. Max Temperature.....Mid 60s. Winds...............East winds around 10 mph. Sunrise: 06:01 AM CDT Sunset: 07:47 PM CDT $$