While some fall forecasts predicted an early burst of cold weather for Toronto, October has kicked off with a heat wave after an already unseasonably warm first few weeks of the season.

The summerlike weather with its sunny skies and near-30 C temperatures has already broken heat records just a few days into the month, with Tuesday's measure of 28.3 C marking the hottest October 3 in the city since records began in 1840.

The only time temps came even close to this high on this date was in 1898, when the thermometer hit 27.2 C.

🥇With a ~2pm high of 28.2°C, today is Toronto's hottest Oct 3rd since records began in 1840.
byu/YOW-Weather-Records intoronto

For those of us who have been eagerly anticipating spooky season and the chillier climate that comes with it, we are set to be uncomfortably sweaty for the rest of the month, as The Weather Network is predicting a continued bout of unusual heat for this time in autumn.

The culprit is an Omega block, caused by an upper level high pressure ridge flanked by low pressure areas.

"This ridge is part of an active jet stream that's swooping and arching its way across the country to begin the month. These troughs and ridges tend to move along in a hurry when the jet stream is this imbalanced, but some patterns force the flow to grind to a halt," the authority wrote in a post about this week's stifling conditions.

"This sequence is a little bit like kinking a garden hose to make the water stop — but, instead of stopping up the winds, it just stops the jet stream from progressing along."

Daytime highs will remain in the upper 20s C over the next week or so for much of Ontario, potentially smashing more long-standing weather records in the process and delaying the development of the fall colours that the province is known for at this time.

The streak should end in most of the province by the long weekend, bringing the mercury down 15-20 C for Thanksgiving.