How hot is it supposed to get tomorrow?

What difference does one degree make when you’re in the midst of a heat wave?

Not much, according to Dave Phillips, senior climatologist at Environment Canada.

The agency had previously predicted the daytime high for Thursday to be a record-breaking 38 C, but has now revised the temperature to 37 C.

Environment Canada uses computer models to make their predictions, which are based on existing conditions. 

“It’s trivial, the fact that it was 38 and now it’s 37. It’s just that, closer to the date, one becomes a little bit more certain of what the temperature is going to be,” Phillips said.

“We’ll have to wait and see what tomorrow is going to be. Maybe it’ll be 36, maybe it’ll be back to 38.”

Another possible explanation, Phillips says, could be that because yesterday’s temperatures did not reach above 30 C, it may have helped to dissipate some of the heat. 

Or it could just be that the temperature was rounded down based on a tenth-of-a-degree difference, he said.

“I wouldn’t read too much into that,” Phillips said.

Based on records taken at Pearson, which date back to 1937, there have only been five occasions when the temperature soared above 37 C — the last time being almost a decade ago on Aug 8, 2001.

If Thursday’s temperature reaches above a sweltering 38 C, Toronto may break the record set in August 25, 1948 at 38.3 C, Phillips said.

-- Amanda Kwan, Staff Reporter

Comments

[Ivan]

There are some records that I'd rather not have broken.

[William Hepburn]

The all-time Toronto record is 40.6 C set downtown on July 8, 9 & 10th, 1936 - one year before records began at Pearson. Downtown records go way back to 1840. So... Toronto would need to reach 40.7 C to break the all-time record.