Toronto could be in for two straight days of record-breaking heat as trick-or-treaters gear up for Halloween.
This fall has been unseasonably warm in Toronto. There hasn’t been a single day this October when the high temperature dipped below 10 C, according to weather data measured at Toronto’s Pearson Airport.
On Wednesday, heat records were smashed across the province. Temperatures reached 23.1 C in Toronto, breaking the 70-year-old record of 21.7 C set in 1946 and 1950.
A weather summary compiled by the federal government shows that 22 cities and towns across Ontario also broke temperature records on Wednesday, including Ottawa, Windsor, Guelph, Kingston and Kitchener-Waterloo.
The record-breaking heat could extend to Thursday, according to Global News’ chief meteorologist Anthony Farnell.
“In Toronto, it will likely be the second straight record-breaking day if we manage to top 22.8C at Pearson Airport. This means that for kids and adults that have lived their entire lives in the GTA, this will be the warmest Halloween of their lifetime,” Farnell told TorontoToday.
The record for the hottest Toronto Halloween on the books was set in 1971.
The current warm temperatures are expected to break by Friday and stay at bay through the weekend, but Farnell predicted “another round of unusual or even record breaking warmth is possible next Tuesday.”
The reason behind this warm front, according to Farnell, is a “very amplified weather pattern across North America [that] is leading to cool conditions across the west and these very warm temperatures in the east.”
The meteorologist expects Toronto won’t be the only location in Canada to break temperature records — Quebec and Atlantic Canada are also seeing unseasonably warm weather.
Farnell said it’s “impossible to directly associate any single record high temperature with climate change” but when looking at the bigger picture, the difference is noticeable.
“We are living in a warming world and we're now much more likely to break high temperature records than low temperature,” he said.
A pilot program under Environment and Climate Change Canada is seeking to understand the degree to which human-caused climate change is impacting heat waves in the country.
The Rapid Extreme Weather Event Attribution system analyzed heat waves in eastern and western Ontario in the month of September and found these events were “more likely because of human influence on the climate.”
In eastern Ontario between September 11 to September 21, daily temperatures were nearly 8 C above normal, with a peak high temperature of nearly 26 C. In western Ontario, daily temperatures were over 10 C higher than normal from September 13 to September 21, with a peak high of nearly 25 C.
The normal temperature used in the comparison is the “average of high temperatures observed from 1991-2020 in the month surrounding the heat wave, for that region,” according to the system’s website.
Farnell said climate change can contribute to more weather “blocking,” which is when a high or low pressure weather system settles over a region and prevents other weather systems from passing through.
“This can produce some incredible rain and floods like we are seeing in Spain this week, but it can also lead to several days of record warmth like we are now seeing in southern Ontario,” he said.
