If your fall jacket is still stowed away in a closet and yoursummer wardrobe is still in rotation, you and the rest of Toronto woke to a rude awakening this morning, temperatures dropping to just above freezing after an unseasonably warm start to the fall season.

Toronto is now shivering for the first time since we last hit the low single digits in May, as the mercury plummeted from well above to just below seasonal averages.

A wave of cooler air is pushing south across eastern Canada, arriving weeks later than usual. Some areas of Ontario are seeing the season'sfirst dusting of flurriestoday, thoughsnowy weatheris still a bit further away in Toronto.

Big upper level trough bringing in seasonal conditions to Ontario#阿nstorm#阿nwxpic.twitter.com/McPjE295ZF

— Melinda Singh TWN (@WxMelinda21)October 22, 2021

But up until today, it's been really warm.

The Weather Network reports that there have been ten October nights where temperatures measured at or greater than 15 C on Toronto Island through Oct. 18.

As of Oct. 21, there have been 16 days with minimum temperatures recorded at or above 10 C this month on Toronto Island, tying a record 2007 and 2017. Based on the forecast for the next nine days, this record is likely to be shattered.

Yesterday was#TorontoIsland's 16th day with minimum temperature >10°C this October which raises 2021 from 3rd to 1st place for the most during October. Just 1 more day to break the all-time record.#TOWx#ONWxpic.twitter.com/pZA47HsW9D

— Toronto Weather Records (@YYZ_Weather)October 21, 2021

We're a few weeks late for sweater weather, and it looks like winter jacket weather will be delayed too. It was expected that Toronto could see snow as early as mid-October, a window that is quickly closing as Halloween approaches.

The jet stream has created a temperature divide cutting the continent in two, with the complete opposite weather unfolding in western Canada. Vancouver, known for its milder climate compared to Toronto, has registered no days with temperatures over 15 C through October.

Northern communities are also having a much milder fall. In James Bay, Waskaganish, the territory of Eeyou Istchee, 900 kilometres north of Toronto, it's typical for the first frost to occur in late September. The community didn't get frost this year until the morning of Oct. 19.

And as much of Canada waits for the big chill to arrive, places known for hot weather like thestate of New Mexico, and even Mexico itself are witnessing temperatures below freezing this month.