Municipalities are using less salt this mild winter. (CBC News)

The mild winter is bad news for workers at the Windsor Salt mine.

They would normally be working six days a week this time of year, but are now working just five because demand for de-icing products is down.

Two workers on probation at the mine have been laid off.

"It's nice to get a few breaks in the weather here and there. But we're looking at the livelihood of a couple hundred people," said Bill Wark, the CAW union representative for workers at the mine. "We want to see everyone employed."

The Windsor salt mine distributes de-icing and industrial salts throughout the Great Lakes region, but municipal road crews have needed to use little salt this winter.

"Everybody's apprehensive," Wark said. "Hopefully we'll get some winter yet. There's still a little bit of winter left to be had.

"Hopefully, we can get some of the more typical winter for the remainder of the season."

Almost on cue, Environment Canada predicts a flash-freeze is possible in parts of southern Ontario Friday as a blast of Arctic air moves through the region.

A special weather statement from the agency says travel could be difficult in many regions because of wet snow on roads quickly freezing.

Forecasters said the system is expected to reach the traditional snow belts Friday afternoon, and a line from Windsor through Toronto to Ottawa in the evening. There could be up to 10 centimetres of snow across parts of the southwest through Niagara to Hamilton, with up to four centimetres around the Toronto area, and lesser amounts farther north and east.