“First, you need the right weather. It’s got to be cold to make snow, and we still depend on nature for freezing temperatures. If the humidity is low enough, you can make snow at 30 degrees, but temperatures in the teens are perfect.
Next you need water, lots of it. Covering a ski slope takes a gigantic amount of water. To blanket one acre of slope in an inch of snow takes about 12,000 gallons of water. A good-size ski run may measure 30 acres or more from top to bottom. And a ski run needs at least a foot of snow to be credible for skiing. So, just for a single run, you have to pump more than 4 million gallons of water up the hill — enough to fill 300 backyard swimming pools. A big ski resort can burn through 10,000 gallons of water every minute when it is making snow.”