TORONTO -- On the heels of a colder-than-normal April, early May might not be shaping up the way Ontarians had hoped it would.
On Tuesday morning, Toronto started the day with a low temperature of -0.4 C at Pearson International Airport – not a record-setting low, but the first time in 15 years that the city had dipped below the freezing mark in the month of May.
It’s expected to happen again this week, with lows forecast below 0 C on Friday and Saturday mornings.
So, why so chilly?
You may hear the term "polar vortex" tossed around this week. The polar vortex is an area of low pressure and cold air surrounding both the north and south poles. It always exists there, but strengthens in the winter months.
In a pattern like Ontario has this week, cold air sinks south from Canada's artic down into the province.
This week’s pattern could end up leading to record-breaking cold temperatures as we head into the weekend – just in time for Mother’s Day.
Not only will it be colder than normal, but snow will be possible in some areas this week, too.
Snowfall in May isn't unheard of in northern portions of Ontario, but it is unusual for southern portions of the province. As we inch closer to the weekend, flurries are expected to fly in many areas.
There could also be rounds of graupel - small snow pellets, often mistaken for hail.
For anyone hoping to get out into the garden, this weather pattern isn’t ideal, either. Cold overnight lows mean the potential for frost – and Environment Canada has already issued advisories for portions of southern Quebec, including Metro Montreal.
