Actually, you'd be surprised at how infrequently this happens. DEN gets a lot of snow, but with 6 runways and a huge snow removal operation, it's one of the best airports in the country at dealing with the snow and staying open in bad weather conditions. I've only had two weather cancellations in the past five years - and both times, it was weather on the east coast, not weather in DEN, that did it (this past winter's snowstorms were the worst!). I've had as many delays at DEN for summer thunderstorms as I have for snow - not many of either.