Weather conditions

Likely the most reliable characteristic of the weather in Banff National Park is its variability. The weather at one point in the park may be quite different from that of other points relatively near by. At one specific location the weather can vary considerably from year to year, and from day to day, so be prepared! Even if it is warm and sunny at the trailhead, take rain gear and a sweater. You might need them by the time you reach your destination.

The weather can also change dramatically throughout the day. The dryness of the air causes temperatures to vary considerably from night to day. The temperature on a summer night can drop to a few degrees above freezing even if daytime temperatures climbed into the upper twenties.

  Vacationing in such a variable climate means thinking ahead. If you plan to ski, hike or drive in (or into) circumstances where the weather could be a danger, be sure to get the most up-to-date condition reports possible. The Visitor Centres in Banff National Park can provide you with current conditions. The Weather Office in Banff has an up-to-date recorded message that gives the daily forecast, and any advisories or warnings for Banff and the other mountain parks. Their number is (403) 762-2088.

There are certain constants that continually affect Banff National Park's weather: the Park's latitude, the Pacific air from the west, the mountains that surround and fill the Park (particularly those of the Continental Divide), and the occasional spurt of continental air from the east.

Like any place, the Park's global latitude accounts indirectly for some of its weather patterns. In winter, the sun stays up for only a short while and hits the ground fairly obliquely, providing relatively little heat and keeping temperatures low. In summer, the sun stays in the sky for a relatively long period of time, but its rays hit the ground at a fairly oblique angle, diminishing its warming power.

The prevailing westerly winds are perhaps the most influential factor in Banff's weather. These winds bring moist Pacific air from the ocean, across British Columbia toward Banff National Park. As this moist air is forced up over mountain peaks, it cools. The cool temperature causes the moisture in the air to condense and precipitate out. As the air descends on the downwind side of the mountain, it warms and stops precipitating.

The last great hurdle that the moist Pacific air has before entering Alberta is the mountains of the Continental Divide. This formidable barrier pushes the air to new heights, lower temperatures, and wrings a great deal of the remaining moisture out of the air. As the now dryer air descends and warms, it flows through the less contiguous Front Ranges, depositing much less precipitation.

On occasion the wind will come from the east, pushing continental air up over the mountains. In this case, the normal situation is reversed, and precipitation is deposited on the Front Ranges. This upslope weather happens in the early summer, and also gives Banff the occasional mid-winter cold spurt.

Climate, more than any other factor, determines what will exist in an ecosystem. The climate is the primary determinant of what types and amounts of vegetation will exist in an area. The types and amounts of vegetation determine the types and numbers of herbivorous and omnivorous animals. At the top of the ladder are the carnivores, dependent on all below them. So the answer to the above question is, "Climate influences everything in Banff National Park!"

Wildlife habitat is sculpted by the weather. During the winter some animals, like bears, can hibernate. Others animals, like voles, adapt by traveling through tunnels in the snow. Still others, like bighorn sheep, are dependent on the grass that hides beneath the snow. In the winter, they must make their way down toward the montane valleys or to the few windswept slopes to find food. Their long term populations are determined by the numbers that their winter habitat will support.

Humans in Banff National Park have habits similar to those of the wildlife, and we respond to the changes in weather in a similar way. In winter, we may choose to hibernate in our own way. Those that do not, stay pretty much to the montane valleys, perhaps traveling to the few high mountain slopes where the conditions are right for skiing. In the summer we again range high up into the mountains to hike, ride horses, bike, climb.

Visitors to Banff National Park must remain aware of the effect that climate has on all the animals (humans included) in the Park. Make sure that you are informed, and prepared to enjoy and endure all of the kinds of weather that you will encounter. Please be sensitive to Banff's wildlife and to their efforts to respond to the park's climatic cycles. Remember that humans share Banff's valleys and mountains with the park's wildlife and vegetation.