Thursday may be Toronto's hottest day ever

(Hajop Ohannessian of Toronto practices yoga along the shore of Lake Ontario on Tuesday. With temperatures reaching the upper 30s many Torontonians are heading to the water for some hot weather relief. TARA WALTON/TORONTO STAR)

Keep your fan on high and your water bottle handy: Thursday could be Toronto’s hottest day ever.

The temperature is expected to reach a scorching 38 C. Toronto has only been that hot once, when it reached 38.3 C on August 25, 1948 according to measurements at Pearson airport.

Factor in the humidex and Thursday will feel like somewhere in the mid to high 40s.

If it doesn’t quite beat 38.3, Thursday could still be the hottest July day on record, beating out the 37.6 C high on July 7, 1988. Temperature records at Pearson have been kept since 1937.

Friday is projected to cool down to a more reasonable 32 C, but highs above 30 C are forecast through the weekend.

“We’re talking about excruciating temperatures,” said David Phillips, a senior climatologist at Environment Canada. “It’s very unusual.”

Overall, nine days this month have reached temperatures higher than 30 C. “We’ve already had a year’s worth of days above 30,” Phillips said.

The extreme heat is caused by a high-pressure system sitting over the city that’s warding off weather and keeping the jet stream well to the north, Phillips said.

The smog that sometimes accompanies hot weather is nowhere to be seen, though. The city’s only had one smog day this summer. In 2005 — a similar year temperature-wise — there were 20 by this time, Phillips said.

There have been fewer smog days partly because of improved air quality, said Kate Jordan, a spokesperson for the Ontario Ministry of Environment.

In the past eight years, the province has seen reductions in fine particulate matter and nitrogen dioxide — the two main ingredients in smog, Jordan said.

Reflecting the soaring temperatures, city officials expect to issue an extreme heat alert Wednesday which will likely last until Sunday.

Dr. David McKeown, the city’s medical officer of health, said elderly people, those with medical conditions and isolated people without air conditioning are most at risk during prolonged hot periods.

“I am asking everyone, including landlords, to check on those at risk,” he said.

If an extreme heat alert is called, Toronto Public Health will open seven cooling centres across the city. Some city pools may extend their operating hours.

EMS chief Paul Raftis said it’s important for people to drink water, avoid too much outside activity between 11 a.m. and 4 p.m., and check up on family and friends for symptoms of dehydration.

The coroner’s office reported six deaths from heat-related causes last year in Toronto. But Dr. McKeown said statistical analysis shows an average of about 120 deaths per year from heat-related causes.

No such deaths have been reported this year.

Those in need of assistance can call the Canadian Red Cross heat information line at 416-480-2615, between 9 a.m. and 9 p.m.

— Michael Woods, with files from Amanda Kwan

Comments

[Shayne]

at Pearson yes.... but an official temperature of 40.6 was recorded in 1936 at the now semi-defunct Toronto downtown weather station.

[Stephanie Robinson]

Please, editors, put some staff on the story that obviously follows this one: why are there fewer smog days? What have we done - or not done- to make the air quality better?What has reduced fine particulate matter and nitrogen dioxide?

People need to be reminded that previous actions (sacrifices) may have led to this good outcome. Please, spend some money on letting reporters get some depth to their stories!@

[Derek Rubinoff]

Wow, Toronto to hit 100!

[Jordan C]

The article fails to mention something important please,do not leave your dog or other pets in the car.It is far to hot for them in this weather and they could become seriously ill or even die in tempatures like these.

[Wallhouse Wart]

I really wish newspapers would quit with the "hottest ever" or "coldest ever". Until you have records that reach back more than 1840, you can't really say that. In fact 1948 is within living memory so this isn't all that unusual. We do get extreme hot and cold every so often.

[Mg]

Thursday may end up as the record for Pearson, but it will still have a way to go to make it as Toronto's hottest day ever. The downtown location hit 39.4 on July 3, 1911, and then 40.6 for three days in a row, July 8-10, 1936.

http://climate.weatheroffice.gc.ca/climateData/dailydata_e.html?timeframe=2&Prov=ON&StationID=5051&dlyRange=1840-03-01%7C2011-04-17&Year=1911&Month=7&Day=01

http://climate.weatheroffice.gc.ca/climateData/dailydata_e.html?timeframe=2&Prov=ON&StationID=5051&dlyRange=1840-03-01%7C2011-04-17&Year=1936&Month=7&Day=01

[Chrisgo]

It's been windier than usual. I would imagine that wold have something to do with less smog.

[Highgate]

I am sure readers working in in the Arabian Gulf will sure be impressed with your "record."

[Karinky]

Huge reduction in smog days - could this be due to Liberal policies? Let's give credit where credit is due.

[Mark]

What's the actual temperature in Toronto? Pearson is what, 25km's away from the downtown? The island is well, an island in the middle of the lake. It's a known phenomenon that urban climates are always even warmer than outlying regions or lake bound islands. I guarantee you that 38c at pearson is going to be 40+ in the heart of Toronto. Lets start getting some legitimate Toronto reporting for weather and not just our airports. Tall buildings, lots of concrete, Wind changing building. Vehicular traffic all bring temperatures up in Urban centres.

[Jeff Graham]

Do not leave kids or pets in hot cars for even a few minutes. I live in the southern US where we have had temps over 100 F for weeks and it will be 106 F today. Every year people and pets die due to being left in hot cars. Stay cool TO.

[Cam]

I hope the power grid can supply enough electricity for all of our air conditioners. If we get black/brown outs people are going to die in the heat.

[VIP]

"Thursday may be Toronto's hottest day ever".
Do your homework before you write; July 5, 1936 was 45 degrees C. It only took me 2 minutes to look it up.

[Jeff]

@Cam, can you provide a link to back uip your July 5, 1936 was 45 degrees C claim? I see in Saskatchewan on that day it reached that temperature, can't find anything saying toronto reached that same temperature.

"Hottest Day on Record - July 5, 1937. The highest temperature ever recorded in Canada was reached at Midale and Yellowgrass, Saskatchewan when the mercury soared to 45°C."

here's a link to my source:http://ontario.hazards.ca/historical/Heat_Ontario-e.html

it may have only taken you 2 minutes to look that up, but you failed to either read the articles headline "Thursday may be Toronto's hottest day ever" key word here being 'Toronto'.