Planning for the weather is an important factor for making your trip to Seeley Lake a success, especially when you're splurging. The hottest months are usually July and August, with an average temperature of 15°C, while the coldest months are December and January, with an average of -6°C. The snowiest months in Seeley Lake are January, February, October and April, with each month seeing an average of 26 cm of snowfall.