The heat warning that was posted Monday for the Barrie area is expected to be lifted later on Thursday, according to Steven Flisfeder, a warning preparedness meteorologist for Environment Canada.
The past few days of heat and humidity has given the region a dress rehearsal for summer which officially arrives at 4:50 p.m. today.
While most people have their own tolerance for heat and humidity, Environment Canada has its own criteria for what triggers a heat warning, and it varies across the country.
"The criteria for a large portion of southern Ontario including the Barrie area is for two consecutive days of daytime highs of 31 degrees and an overnight low of 20 degrees and/or a humidex of at least 40," explains Flisfeder
Looking ahead to the weekend, he says there will still be fairly high humidity, just not as bad as we've been seeing.
"The temperatures are expected to drop off compared to what we've been seeing, so daytime highs over the next few days in the 25 to 27 degree range, and with the humidity, we probably should be in the low to mid 30s. It will probably feel uncomfortable, but in comparison, not quite as uncomfortable."
Though exact details are still to determined, there is a chance of heavy showers on the weekend, according to Flisfeder, possibly in the late Saturday and early Sunday timeframe.
Heat warning criteria in Ontario from Environment Canada:
Extreme southwest (Essex and Chatham-Kent counties)
Issued when 2 or more consecutive days of daytime maximum temperatures are expected to reach 31°C or warmer and nighttime minimum temperatures are expected to fall to 21°C or warmer.
Or
Issued when 2 or more consecutive days of humidex values are expected to reach 42 or higher.
Ontario - North
Issued when 2 or more consecutive days of daytime maximum temperatures are expected to reach 29°C or warmer and nighttime minimum temperatures are expected to fall to 18°C or warmer.
Or
Issued when 2 or more consecutive days of humidex values are expected to reach 36 or higher.
Remainder of southern Ontario (including the District of Parry Sound)
Issued when 2 or more consecutive days of daytime maximum temperatures are expected to reach 31°C or warmer and nighttime minimum temperatures are expected to fall to 20°C or warmer.
Or
Issued when 2 or more consecutive days of humidex values are expected to reach 40 or higher.
