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Canada's Top Ten Weather Stories For 2005

Table of Content

4. From a Bummer to a Hummer of a Summer

At times during the summer, residents across Ontario and southern Quebec either enjoyed or endured bouts of torrid heat and insufferable humidity. Combined with a record number of smog days, it was easily one of the hottest, sweatiest and dirtiest summers ever. And what a contrast to 2004 when summer went missing - it was either too cool, too wet or too cloudy for the likes of most people. If 2004 was the year without summer, 2005 was the year summer wouldn't end.

The summer of summers began with the warmest June ever, and the record-breaking trend continued into July, August and beyond. For traditional hot spots such as Windsor and Toronto, June-to-August was the warmest on record. Of significance was the number of hot days (>30°C) in Toronto. Normally, the city gets approximately 14 hot days a year. In 2004 there were only 3 hot days, but in 2005 there were a whopping 41! Montreal was also well above its average of 8 hot days per year, logging in with 23 for 2005. In contrast, there were only 2 hot days in 2004. Back in Toronto, the city issued eight heat alerts and 18 extreme heat alerts for a total of 26 heat days. The previous record was 19 in 1991. If anything, the summer heat was uncommonly relentless with few breaks between each episode.

For many it was the oppressively high humidity that evoked most of the complaining and for good reason. At Toronto, the number of days with humidex values greater than an uncomfortable 35 reached 44, tying the record in 1955 and 2002. The summer also featured the longest-ever bout of jungle-like humidity lasting 13 consecutive days beginning on July 10. But while daytime sweats can be eased by swimming pools and workplace air conditioning, it was the high night-time minimum temperatures that often led to much tossing and turning. In Toronto, minimum temperatures were a sweltering four degrees warmer than normal. Further, there were 25 nights in which the minimum temperature did not drop below 20°C (i.e. tropical nights), breaking the previous record of 19 in 2002.

With excessive heat, loads of sunshine and sluggish air circulation, frequent smog days were inevitable. At times, the heavy air was almost unbreathable and the smog was so thick that the CN Tower was only partially visible from a distance. The Ontario Ministry of Environment issued a record-breaking number of smog advisories from May 1 to September 30, covering 42 days across the province. Advisories ranged from 38 in Toronto to 10 in Sault Ste. Marie. June had exceptionally bad air, with smog advisories covering 20 days (two-thirds of the month). One episode lasted an unprecedented eight days. In Quebec, there were five actual smog episodes (not advisories) from May to September, counting 13 days in total, ranging from 12 days in Montreal to 4 days in the Laurentides and Quebec-Beauce. The longest bad air episode lasted six days from June 8-13 across Montreal and in the region of Drummondville / Bois-Francs.

At least six deaths in Toronto were blamed on the relentlessly hot summer, and that's likely just a fraction of the real mortality rate due to heat and smog. It was no surprise that power consumption was at an all-time high. Ontario's electricity manager issued more than a dozen emergency appeals to reduce power consumption in order to avoid rotating blackouts. With megawatts of power flowing at record levels, the province had to dim voltage by 5%.

Yet, the majority of residents seemed ecstatic over a summer that just went on and on. By Labour Day, summer came in as the warmest on record. But it didn't stop. The 6-month period from June to November turned out to be the warmest on record across parts of Ontario and Quebec. All people were talking about was the long stretch of bonus warmth, especially in the fall. It was so pleasantly warm for so long that many residents either felt guilty or concerned that somehow they were soon going to pay for the excess of delightful weather.