If you’re hoping to get lost in the rain on your romantic getaway, take a look at these details about year-round temperatures in High River: The hottest months are usually August and July, with an average temperature of 15°C, while the coldest months are December and February, with an average of -7°C. The snowiest months in High River are March, April, January and February, with each month seeing an average of 38 cm of snowfall.