SXUS45 KMSO 042330 RECGPI Recreation Forecast for Flathead Lake National Weather Service Missoula MT 505 PM MDT Sat Jul 4 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. .Tonight...Mostly clear. Lows in the upper 50s. Variable winds up to 10 mph. Gusts up to 25 mph in the evening. Waves less than 1 foot. .SUNDAY...Sunny. Highs in the upper 70s. Variable winds up to 10 mph. Waves less than 1 foot. .SUNDAY NIGHT...Mostly clear. Lows in the mid 50s. Variable winds up to 10 mph. Waves less than 1 foot. .MONDAY...Mostly sunny. Highs in the mid 70s. Variable winds up to 10 mph. Waves less than 1 foot.