The climate in Sault Ste. Marie is temperate, which means that the city experiences four distinct season changes. Although it can be visited throughout the year, certain months are much more comfortable for being outdoors than others.
Summers in Sault Ste. Marie are very comfortable, as they are generally rather mild. On average, the hottest months of the year are July and August, during which time the daily high temperatures will generally hover in the low to mid 20's Celsius (70’s Fahrenheit). The nighttime temperatures during these months will generally drop to the 10°C-13°C range (mid to lower 50’s Fahrenheit), so bring along a warm layer. Most people choose to visit Sault Ste. Marie around these summer months.
Winters in Sault Ste. Marie are very cold. The coldest months of the year on average are January and February, during which time the daily high temperatures will only reach the -4° to -7°C zone (lower 20’s). The nighttime temperatures during these months will generally fall all the way to the -7° to -18°C range (single digits) and often lower.
Sault Ste. Marie has a rather wet climate, and during any month there is a chance for precipitation. However, on average, the wettest months of the year are September and November.
For weather forecasts, current conditions, and up-to-the-minute weather warnings, check out Environment Canada's official Sault Ste Marie weather page (this page is also available in imperial units).
For very detailed climate information, including precipitation, wind, temperature, and snow cover, Environment Canada has a Sault Ste Marie climate page.