Weather is probably a major factor when you plan your trip to Harvey, 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 19°C, while the coldest months are February and January, with an average of -9°C. The snowiest months in Harvey are April, October, March and December, with each month seeing an average of 22 cm of snowfall.