If you planning to travel to St. Mary Lake, Glacier National Park, United States, here is your 6-day travel weather forecast to make sure you have all the essentials needed during your stay. Start your day when the sunrises at 3:21 PM. The temperature feels like 20.9 with a humidity level of 73 so dress accordingly. Cloud coverage is 63 percent with visibility at 7.1 percent. Today’s UV index is 2, don’t forget the sunscreen if you need it! Today’s winds are traveling west-southwest at a speed of 27 MPH. At the end of the day don’t miss the sunset at 11:40 PM.