The mercury is set to plunge this week as a cold front makes it way into southwestern Ontario.
Environment Canada is forecasting a 40 per cent chance of flurries with a low of minus 3C Friday night.
Meteorologist Gerald Cheng, says there's potential for some record-setting temperatures as the cold front makes its way into the region.
Cheng calls the this past weekend's warm temperatures, just a tease.
"We can forget about last weekend because it's going to be a world of difference this weekend. Things are on their way down," he says. "The polar vortex is expanding and allowing that cold air the surge where we are and that's why we are looking at some very cold temperatures."
Cheng says if you've started any gardening, you may want to bring your plants inside.
"Friday night is the coldest period and we could be breaking records. Recognizing that a lot of garden centres have opened up and people are buying plants, certainly you'll want to think about that because temperatures will go sub-zero," he says.
Cheng calls a cold like this rare this late in the spring.
"Friday is a big drop in terms of temperatures. Normally, for daytime highs, we should be close to 20C and it's going to be nowhere near that," he says "We will be at least 10-degrees off. So this is a quick snap, a cold snap in May."
The forecast for Saturday shows a slight return to warmer conditions with sunshine and a high of 11C expected.