Waterton has highly variable mountain weather which can change quickly.
Summers are brief and cool and winters are mild and snowy, with frequent warm spells caused by chinooks. As a result of these chinooks, temperatures can rise dramatically in short periods of time.
While April and June are the wettest and cloudiest months, July and August tend to be the sunniest and warmest. With September and October come breathtaking fall colours.
Although November and December bring the start of winter, January and February are the coldest months, with temperatures that can drop to minus 40°C (minus 40° F). Average winter snowfall in the village is 575 cm (225 in), while much more falls in the mountains.
Wind is the most noticeable aspect of the weather in the park. Waterton is the second windiest place in Alberta after the Crowsnest Pass. Daily winds average 30 km/h (20 mph), but gusts of 120 km/h (75 mph) are not uncommon. The highest winds blow in January and November.
Never underestimate the power of weather. Before heading out on a day trip, a hike or an overnight camping trip, check the local weather forecast. This will help you plan - but be prepared for changes in weather.