Mid-December - March
Peak travel season in Whistler is December 15 through the middle of March—particularly the Christmas-New Year holiday break, for which travelers must book far in advance and expect to pay premium rates. Though the ski slopes often open by mid-November (and there is often a huge dump of snow then), inclement weather, which at a ski resort is rain, is possible into Christmas. While Whistler often reports prodigious snowfalls in the early season, avid skiers should remember that the area’s many alpine bowls hold huge boulders that are often not covered with adequate snow until mid-January. Best skiing in Whistler is often late April, even early May, when fresh snow is common up top, sunny days are the norm, and virtually empty hotels bring astounding deals. Bargain hunters can often find packages that offer room and a ski pass (ordinarily $85) for little more than $100 a night.
October - November, April - May
With the exception of November’s Cornucopia festival, for which Whistler is full, these off-season periods between winter and summer are incredible bargains. Skiing usually persists into early June (and into July, on Blackcomb’s Horstman Glacier); clear autumn weather is possible, though by no means guaranteed, through the end of October. In these bracket months you might need shorts, you might need parkas.
Surprise: More visitors come to Whistler in summer than in winter. However, the impact is distributed over a longer period than the height of ski season, so summer prices are usually moderate. The weather shifts to mountain summer around June 15, with daily highs in the 70s, a chance of thunder showers (sprinkles, usually) in the afternoon and cool nights in the upper 40s. This regime lasts through mid-September, sometimes longer. Midsummer, with light lasting past 10PM, is delightful.