Weather is only one factor, but it can really affect your travel plans, especially when you are planning a longer stay in Teton. The hottest months are usually July and August, with an average temperature of 18°C, while the coldest months are January and December, with an average of -5°C. The snowiest months in Teton are January, February, March and December, with each month seeing an average of 31 cm of snowfall.