It felt like Toronto saw all seasons this weekend. Why ‘whiplash weather’ is common in April

People carry umbrellas while walking past a Toronto supermarket during a downpour of rain on Tuesday, Sept. 27, 2022. THE CANADIAN PRESS/Alex Lupul

It was hard to dress for the weather this past weekend as Toronto saw rain, snow, and sunshine in the span of 24 hours, bringing what may have felt like all four seasons to the city. But this sort of “whiplash weather” is common this time of year, according to one climatologist.

At around noon on Saturday Toronto had a temperature of roughly 19 C and then 24 hours later, that temperature dropped nearly in half to 8 C.

“The winds were coming from the southeast at 10 (a.m.), so this warm air coming up from the United States into Toronto and it was delightful,” climatologist David Phillips said in an interview with CTV News Toronto.

“You had some rain coming, you had about seven millimetres of rain come around noon hours, so it was clear in the morning, but cloudy in the day and it was raining at noon.”

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By Sunday, winds were gusting up to 33 km/h at around noon, Phillips said, with snow flurries reported in some parts of the city later in the day.

“Four seasons in one day, certainly in a 24-hour period,” Phillips said. “So really, all of the elements of weather were changing, the fact that you went from rain to snow, from light winds or moderate winds from the south to strong winds from the northwest, we saw the temperatures change … it was really a good, classic kind of contrast between warm air, cold air, but it’s also exactly what April is about.”

Transition between seasons

Phillips says this particular month is “cruel” because any sort of weather can happen, as April serves as a transitionary period between seasons. This is largely due to the positioning of the jet stream, Phillips says, as it changes its seasonal position from winter to summer.

“That jet stream normally passes over you and so that mixes the weather together,” Phillips said, noting how it effectively wobbles back and forth during this time of year.

When its north of Toronto, which typically happens by May, the city is in warmer, moist air, the climatologist explains, but when it is south of us, like how it is in March, the stream brings on colder air.

When warm air mixes with cold air, that’s when the “weather wars” break out and there are dramatic changes seen in weather, Phillips says.

“(April) is a month where you get rain and snow, you get temperatures that could be double digit and up to 20 degrees and yet, getting days where it’s all freezing morning, noon and night, where there’s no melting at all possible,” Phillips said.

‘Whiplash weather’

Toronto’s weather forecast for the week goes from chilly conditions with temperatures feeling like they’re in the negatives before jumping to the double digits by the end of the week.

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Phillips dubs the pendular weather as “whiplash weather,” as its not dependable and teases various weather conditions. The climatologist pointed to a common phrase spouted by those living around the Great Lakes.

“If you don’t like the weather, wait around for five minutes or drive five miles,” he said.

“We forget the transition seasons … and so what we have to deal with is this in-between weather that one day is this and the next day is that."

This particular April has also been rainier than usual.

So far this month, Toronto has seen 91 millimetres of rainfall, Phillips said, while typically during this period of time, it would see about 70 millimetres of precipitation.

“Even the month that’s famous for April showers was really soggy and saturated,” Phillips said.

The amount of rain seen this year could lead to a less severe forest fire season, as Phillips notes it has started with a wet and coolish beginning.

As for when it will start to feel like Toronto is shifting further into summer, Phillips says residents will have to be a “little bit more patient.”

“I don’t think it’s going to come all of a sudden, I don’t think nature still got the email yet,” Phillips said.

“I mean, some springs only last for four weeks, well, this one has gone a full month and probably looks like another month before we get into the May long weekend.”