Thursday, October 01, 2009


As the park spans the Pacific-Atlantic divide, and ranges in elevation over several thousand feet, many climates and microclimates are found in the park. As with other alpine systems, average temperature usually drops as elevation increases. The western side of the park, in the Pacific watershed, has a more mild climate, moderated by its proximity to the ocean and the warm Alaska current.

This location also makes the western side of the park wetter on average. The eastern side of the divide, more sheltered from Pacific storms, but exposed to cold fronts from Canada, is drier and colder than the west side. Many areas are only accessible during the summer, and possibly the late spring and early fall, depending on snowfall and elevation. Rainfall is frequent in the tourist season during the summer and may persist for days, averaging two to three inches each month. Snowfall can occur at any time of the year, even in the summer, and especially at higher altitudes. Visiting in the early summer is a way to avoid some but not all of the wet weather.

In the spring, however, the nights and early mornings will be substantially cooler, and high-elevation trails, including the popular Hidden Lake Trail at Logan Pass, may still be snow covered. Thunderstorms are common all summer, and normal safety precautions for lightning and hail should be taken. The mountainous terrain ensures that tornadoes are very rare.

The winter can bring prolonged cold waves, especially on the eastern side of the Continental Divide. Snowfalls are significant over the course of the winter, with the largest accumulation occurring in the west. During the tourist season daytime high temperatures average in the 60s and 70s °F (15 to 25 °C), and nighttime lows usually drop into the 40s (7 °C). Temperatures in the high country may be much cooler. In the lower valleys, on the other hand, daytime highs over 90 °F (32 °C) are not unusual.

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