Weather is probably a major factor when you plan your trip to Twin Falls, 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 22°C, while the coldest months are January and December, with an average of 0°C. The snowiest months in Twin Falls are January, December, November and March, with each month seeing an average of 20 cm of snowfall.