SXUS45 KMSO 181230 RECGPI Recreation Forecast for Flathead Lake National Weather Service Missoula MT 605 AM MDT Sat Jul 18 2026 Note: The experimental wave height forecasts are representative of the mid lake waters and downwind shores. Wave heights may be significantly less on upwind shores. .Today...Sunny. Highs in the lower 80s. Variable winds up to 10 mph. Waves less than 1 foot. .Tonight...Mostly clear. Lows around 60 . Variable winds up to 10 mph. Waves less than 1 foot. .SUNDAY...Sunny. Highs around 80 . Variable winds up to 10 mph. Waves less than 1 foot. .SUNDAY NIGHT...Mostly clear. Lows around 60 . Variable winds up to 10 mph. Waves less than 1 foot. .MONDAY...Mostly sunny. Highs around 80 . Variable winds up to 10 mph. Waves less than 1 foot.