Ski areas in Western North America have been reporting record high temperatures in recent weeks with Mammoth Mountain and Timberline among resorts closed to summer visitors due to forest fire danger.

But the start of this week saw a massive temperature drop in a little over 24 hours with the mercury plummeting from the high 80s (and even over 100F in some cases) to the low 30s in the Rockies and other mountain areas nearby.

The result was a late summer snowfall from Alberta (Banff pictured above on Tuesday) and BC in the north down to southern Colorado and New Mexico.

There had been an earlier light snowfall a week earlier reported on high slopes but this time the snow reached base level at a number of resorts.

Taos, New mexico on tuesday)

The first snowfall was reported up in Alberta and BC in Canada with ski areas around Banff reporting their mountains had turned white on Monday.

The snow started south of the border on Tuesday with some resorts in Colorado reported as much as 18 inches (45cm) of snowfall by the end of Wednesday with Monarch Mountain posting the largest reported accumulation at that point and saying more was falling (picture top). For most areas it was more like 5-10 inches.  Aspen also saw a lot of snow (below).

Although not a ski area the town of Fort Collins in Northern Colorado set records having hit 100 degrees Fahrenheit (38C) on Monday then seeing its earliest ever recorded snowfall after temperatures fell more than 60 degrees Fahrenheit to around freezing by Tuesday.

Beartooth Pass on the Montana/Wyoming border, which is the location of the only US summer ski area each late spring/early summer, was closed by the snowfall.

Wolf Creek. Colorado, which has been the first in the country to open some autumns.

So far no areas have announced plans to open any runs and the snow is expected to melt quickly as temperatures return to more seasonal norms in the latter half of this week, but it’s possible some back country skiers will get on it to claim first turns of 20-21 before it goes.

Ski areas are all currently closed to skiers in North America but several expect to open next month including Arapahoe Basin and Loveland in Colorado and Nakiska in Alberta, Canada, if conditions are right.

Wolf Creek, Colorado, on Wednesday