Frost advisory issued across southern Ontario as temperatures dip below freezing

Julie Atchison has the latest forecast for the region

Temperatures remain on the cool side in southern Ontario, well below normal for this time of year, says CTV meteorologist Julie Atchison.

The forecast high in London is 11 C, with a few light showers moving through as a cold pattern settles over the region.

“We have this low-pressure area spinning over Lake Superior, and that is pulling colder air down to the surface,” Atchison says.

The chance of brief, light showers will continue through the late afternoon, with skies becoming mainly cloudy.

The pattern continues Friday, with a mix of sun and cloud and a chance of showers, particularly along the north shore of Lake Erie. London could also see a pop-up shower in the afternoon.

A frost advisory is in effect for Middlesex, eastern Lambton and Elgin counties, stretching to Oxford, Haldimand, Norfolk and the Golden Horseshoe.

Temperatures could dip below the freezing mark overnight, ranging from about 0 C to -2 C across most of the region. Areas along the Lake Erie shoreline are expected to remain slightly milder, near 1 C to 2 C, with similar conditions near Lake Huron.

Interior regions, including Huron-Perth and Grey-Bruce, are expected to hover closer to the freezing mark, raising concerns for sensitive vegetation.

“That could nip some of our beautiful spring flowers,” Atchison says, noting the growing season is already underway. “If you have tender plants, you might want to cover those up.”

Friday’s high is expected to reach 12 C, with a chance of a passing shower and some sunny breaks.

Here’s a look at the rest of the forecast

Thursday: Mainly cloudy with 30 percent chance of showers. Wind becoming northwest 30 km/h this morning. High 11. UV index 6 or high.

Thursday night: Partly cloudy. 30 per cent chance of showers early this evening. Wind northwest 30 km/h becoming light this evening. Low minus 2 with frost. Wind chill minus 5 overnight.

Friday: A mix of sun and cloud. 40 per cent chance of showers late in the morning and in the afternoon. Wind becoming northwest 20 km/h in the afternoon. High 12. UV index 6 or high.

Saturday: Sunny. High 8.

Sunday: A mix of sun and cloud with 40 per cent chance of showers. High 16.

Monday: Cloudy with 60 per cent chance of showers. High 14.

Tuesday: Cloudy. High 15.