Brace for a weekend of weather extremes: a toasty Saturday giving way to a freezing Sunday with possible snow in Denver.

Today the highs could approach 70 degrees, with the warmth continuing Saturday in the lower 70s, Jim Kalina of the National Weather Service said this morning.

But the Big Chill will sweep in overnight Saturday with a 50 percent chance of snow in the south metro suburbs — and possible white stuff in Denver.

Get ready to fire up the fireplace and pick any late-season veggies from the garden.

So-called "highs" Sunday may only reach the upper 30s with lows that night in the mid-20s.

"We're looking for a pretty good freeze," Kalina cautioned.

"There could be some snow in the metro area after midnight Saturday. Or it could be a mixture of rain with some flakes mixed in," he said.

The good news: the storm will move through quickly, reducing the chance it'll drop much snow.