Chicago’s mild winter is coming to an end. And now events like ice castles and ski jumping are back.

Winter should be white. Nobody knows that better than people who depend on snow and cold for a living.

A midwinter meltdown earlier this month forced the Norge Ski Club to postpone its annual ski jump tournament in Fox River Grove. The warmth and rain also shut down skiing at Villa Olivia in Bartlett, canceled the opening of Ice Castles in Lake Geneva, and turned Chicago’s Polar Adventure into temperate tedium.

But now, real winter is back. As snow falls and temperatures drop, all those activities are resuming as soon as organizers can create enough flakes and ice to make them happen.

At the Norge ski jump, which towers more than 150 feet overlooking the Fox River, volunteers plan to use snow guns to blast the hill with enough padding for skiers to land on.

The club is one of the leading ski jump groups in the nation, sending three members of the U.S. Olympics four-man team to each of the past two Olympics.

Norge’s annual tournament is one of the biggest in the nation, attracting jumpers from around the country and thousands of spectators every year. A party atmosphere reigns at the bottom, with food, drinks and rock music.

The event has never been canceled in 118 years, but had been postponed twice, and was again this year, getting pushed back to Feb. 11-12.

Volunteers already made the ski jump run out of ice, with refrigerated tubes underneath to keep it from melting, but the 300-foot-long landing area needs a foot deep of snow.

Because the club uses well water that comes out at about 50 degrees, it generally needs temperatures to stay below 21 degrees to make snow.

“So we’re just waiting for it to get cold,” club President Scott Smith said. “If the forecast sticks, it’ll be top-notch.”

While Wisconsin ski resorts report adequate snow, the annual Ice Castles event in Lake Geneva had to be postponed from this weekend and now will open Feb. 3. The castle was almost entirely built following a cold snap a month ago, but rains melted it almost to the ground.

With temperatures dropping, workers are busy making icicles, placing them on the castle, and spraying them with a sprinkler system to grow the structure, complete with slides, tunnels and an icy throne.

To say the least, it’s been very challenging,” spokeswoman Melissa Smuzynski said. “We are very hopeful and confident they’ll be able to create something beautiful, and at least give people two or three weeks of winter magic this season.”

The site of the castle, Geneva National Resort & Club, also offers brunches with Ice Princesses, dining in outdoor “snow globes” and candlelight sledding.

At Villa Olivia, a small ski hill in northwest suburban Bartlett, the lack of snow prevented skiing, but officials planned to resume scheduled lessons Friday and general skiing as soon as they can make enough snow.

On Northerly Island, the Chicago Park District held its Polar Adventure Day Jan. 21 with no snow. Hopes are high there will be enough snow to have husky dog sledding and snowshoeing for the next Polar Adventure Feb. 25.

The recent interruption of winter was out of character for Chicago. The city had 29 days in a row with above normal temperature, the National Weather Service reported, but that streak ended Thursday. The city also has 8 fewer inches of snow than normal by this point.

The mild weather was due partly to cold waters in the Pacific, known as La Nina, that affect patterns in the continental United States, meteorologist Matt Friedlein said. The Chicago area also got lucky, dodging storms that dropped more than 50 inches of snow in Minneapolis and lake-effect snows that dumped more than 100 inches on Buffalo, New York.

But now the jet stream is buckling farther south, and we’re entering a colder, snowy pattern through early February.

“Most winters aren’t normal in the Midwest — they kind of bounce around,” Friedlein said.

Now that more typical weather is here, he said, “Enjoy the winter.”