Environment Canada has issued a humidex advisory for the city of Toronto for Tuesday and Wednesday.
The humidex is an index that combines the temperature and humidity into one number to describe how hot the weather feels to the average person.
Environment Canada says that the humidex is particularly significant when its value is greater than 30. Tuesday’s humidex peaked at 38.
Tuesday’s high was 29 C, falling to 21 C overnight, while Wednesday is expected to be sunny with a high of 34 C.
If Wednesday’s temperature reaches its expected high, a record will be set. Phillips said the current record for June 8 is 32.2 C, set in both 1950 and 1959.
The weather on June 8 last year was 20.3 C.
Dave Phillips, senior climatologist with Environment Canada, said that Wednesday’s humidex could be as high as 42 or 43. The UV index will be 9 or very high. Phillips expects the “triple H” — heat, humidity and haze.
Environment Canada warns that a high humidex can lead to health problems such as cramps, exhaustion and heat stroke. They advise people to drink a lot of water, avoid working or exercising intensely outside if possible, and take frequent breaks if necessary.
Environment Canada also reminds people to take special care to ensure that pets have plenty of water, are well-protected from the heat, and are not left in hot cars.
Phillips said that Wednesday will probably be the hottest day of the year so far.
“Get used to it,” said Phillips. “We think there’ll be more of these kinds of days.”