Taking the local weather in East Helena into account is an important factor for planning your visit, especially if you plan to spend your trip by the pool. The hottest months are usually July and August, with an average temperature of 17°C, while the coldest months are February and December, with an average of -5°C. The snowiest months in East Helena are February, October, January and March, with each month seeing an average of 31 cm of snowfall.