SXUS43 KGRB 180621 RECGRB WIZ048-WIZ049-180900- Recreational Forecast for Lake Winnebago National Weather Service Green Bay WI 121 AM CDT Mon May 18 2026 .REST OF THE NIGHT...South winds 10 to 20 knots. Patchy fog. chance of thunderstorms. Waves 1 foot or less. Lows in the mid 50s. .MONDAY...Southwest winds 10 to 20 knots. Chance of thunderstorms in the morning, then slight chance of thunderstorms in the afternoon. Waves 1 foot or less. Highs in the mid 70s. .MONDAY NIGHT...South winds 10 to 20 knots. Slight chance of thunderstorms in the evening, then chance of thunderstorms after midnight. Waves 1 foot or less. Lows in the lower 60s. .TUESDAY...West winds 15 to 20 knots. Chance of thunderstorms in the morning. Waves 1 to 3 feet. Highs in the mid 60s. $$