As people in Southern Ontario slapped on sunscreen in the stifling heat, residents in and around Calgary continue to be under a snowfall advisory.

"In a couple of hours of driving you can go from tornado weather to snow tires,'' Dan Kulak of Environment Canada said.

"This is just the way it is on the Prairies in the spring. Now is the time to think about severe weather. ''

Calgary residents awoke to trees bending and breaking under the weight of wet snow with wind-chill causing temperatures to feel like five degrees below zero.

"It was a quarter to five this morning when I heard a snap and pop. I jumped out of bed because I thought someone was breaking into the house," Anton Danielson told CTV Calgary.

Tree branches weighed down with snow broke the power-line outside his house, but there was no other damage.

"Everything is good. The old house is from 1912, so it's seen it before, I'm sure," he said.

Areas around the Calgary airport received 10 centimetres while areas at higher elevations received 15 to 20 centimetres.

"I see snow and slush and it is raining right now,'' Brandon Regnier said after cancelling a tournament at the Wolf Creek Golf Resort.

"This is the most snow I've seen this late in the year.''

ENMAX workers were busy cleaning up fallen branches and power lines while they tried to restore power to affected areas.

A number of fender benders were also reported in the area.

"We're used to snow, but really not this heavy wet snow that we got so late in the year," CTV Calgary's Kevin Rich said.

The wintry weather was caused by a jet stream that came from the northern region of the country.

"It was an upper-level cold low," CTV weather reporter Steve Rothfels said.

Cold lows from the west or south west are normal in the area for this time of year; however this cold low was unusual in that it came straight from the North.

The opposite was true for much of Ontario as temperatures rose into the 30s threatening to break heat records.

The warm weather has also brought a smog advisory, which remains in effect across much of southern and central Ontario.

On Thursday at noon, the air quality rating for southwestern Ontario was poor. In Toronto, temperatures were forecast to rise as high as 32C, which would shatter a record 30.5 degrees Celsius high set on May 24 1991.

The province is urging residents, especially those with respiratory problems, to refrain from heavy outdoor activity.

Hot, dry conditions sparked a forest fire on Wednesday that closed a highway and forced the evacuation of a northern Ontario provincial park.

Relief will arrive Friday as that cold front moves in from the west, bringing scattered precipitation and highs in the low 20s.

Weather across other parts of the country is slightly on the chilly side, but fairly normal for this time of the year.

Thunderstorms are forecast for the interior of British Columbia while parts of Nova Scotia are bracing for frost.

With files from CTV Calgary and The Canadian Press