Weather is probably a major factor when you plan your trip to Riverton, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually July and August, with an average temperature of 20°C, while the coldest months are January and February, with an average of -4°C. The snowiest months in Riverton are April, November, February and January, with each month seeing an average of 27 cm of snowfall.