Toronto is poised to break a heat record set when Lester B. Pearson was settling in to 24 Sussex Dr and Jimmy Gilmer and the Fireballs topped the charts.
The mercury in Toronto is expected to hit 27 degrees Tuesday with a Humidex of 32 degrees.
The standing record for the hottest October 18 in Toronto is 26.7 set in 1963.
"This is pretty rare," Environment Canada Meteorologist Geoff Coulson tells NEWSTALK 1010's Moore in the Morning. "But it's part and parcel to the type of conditions we've had going back to the month of August."
A number of heat records fell that month across southern Ontario with September and October both warmer than normal.
"This particular situation (exists) because we've got a direct pipeline basically from the Gulf of Mexico bringing up this very warm, moist air," Coulson explains.
A cold front is expected to move into southern Ontario late Tuesday afternoon bringing some unsettled weather with it.
Environment Canada says wind gusts of between 60 and 70 km/h are likely. With scattered showers and thunderstorms possible, the agency says gusts could actually hit 80 km/h.
Environment Canada does not expect gusts to cross the 90 km/h threshold which would trigger a wind warning, but forecasters will monitor the situation.