Planning for the weather is a good way to make your trip to South Indian Lake relaxing and enjoyable, especially when you're splurging. The hottest months are usually July and August with an average temp of 58°F, while the coldest months are February and January with an average of -1°F. The snowiest months in South Indian Lake are March, January, November, and February, with each month seeing an average of 11 inches of snowfall.