A fickle fall; Strengthening El Niño triggers a two-faced season

Oakville, Ontario, Sept 22, 2023 – September has already featured record heat, wildfires, frost and threats from the tropics. Is this an indication of what Canadians should expect during the next few months as we make the transition from summer to winter? 

To help answer this question, The Weather Network has released their fall forecast.

“Changeable weather is the trademark of the fall season, but this fall looks to be especially fickle as strong El Niño conditions continue to develop,” said Chris Scott, Chief Meteorologist at The Weather Network. “We expect that most Canadians will see an extended stretch of colder-than-normal weather during the heart of the fall season, which could give the impression that winter is set to start early this year. However, with the strengthening El Niño, we expect that warmer-than-normal temperatures will return during November and continue through December.” 

Nearly all of Canada can expect near or above-normal temperatures for the fall season as a whole as the periods of colder-than-normal weather and early shots of wintry weather will be offset by extended periods of mild weather.   

Much of the country will experience fewer classic fall storms than what we typically see, but a few of the storms that occur will have the potential to be memorable with a risk for excessive rain and high winds for many Canadians.  

What is El Niño?

El Niño is associated with warmer-than-normal ocean water temperatures in the tropical region of the Pacific Ocean to the west of South America. This has an impact on the global jet stream pattern.  

Here’s a more detailed look at the conditions that we expect across Canada this fall:   

British Columbia 

A warm and dry start to the season means that we will continue to deal with wildfires and smoke later into fall than normal. However, temperatures and precipitation should trend closer to normal during the second half of the season. While fall precipitation totals are expected to be below normal, we still have a risk for a couple of high impact storms before the end of the season with a threat for excessive rain. At this point it looks like the start of the ski season could be delayed. 

The Prairies

Warmer-than-normal temperatures are expected to dominate during much of the fall season, but we are watching the potential for a stretch of colder-than-normal temperatures, especially across eastern parts of the region. This will likely include a few shots of early winter-like weather. However, while winter will taunt us at times, we expect that mild temperatures will return and dominate during November and into December. 

Ontario & Quebec

Winter may give us the impression that it is plotting an early arrival this year with shots of chilly weather during October. However, rather mild weather is expected to return during November and continue through December. The alternating periods of warm and cold weather should come close to offsetting each other and result in near normal temperatures for the season. We do have a heightened risk for a couple of high impact fall storms, but fewer storms are expected overall. 

Atlantic Canada

Near-normal temperatures are expected for much of the region, but southern areas should tip to the mild side of normal. We also expect near-normal precipitation totals, but we will continue to keep a close eye on the tropics and the risk for excessive rain events. Aside from the concern for impacts from tropical systems, we expect fewer classic fall storms than normal. 

Northern Canada

Warmer-than-normal temperatures are expected to dominate across western and central parts of the region, with near-normal to slightly colder-than-normal temperatures across eastern parts of the region. Near-normal or above-normal precipitation is expected across the region. 

Keep in mind that even a mild fall can bring dangerous winter weather conditions to parts of Canada with little notice. As we move deeper into the season, Canadians should pay extra close attention to the daily forecast as winter weather conditions can develop and change rapidly. Canadians can be prepared for changeable weather by visiting theweathernetwork.com or by downloading The Weather Network App and creating an account for personalized and up-to-the-minute forecasts.

The Weather Network: Fall 2023 Forecast
Region	Temperature Outlook	Precipitation Outlook
British Columbia	Above normal	Below normal south; Near normal north
Alberta	Above normal	Near normal; Below normal southwest
Saskatchewan	Above normal	Near normal
Manitoba	Above normal west & central; Near normal east	Near normal
Ontario	Near normal	Near normal; Below normal northeast & near Lake Superior
Québec	Near normal; Below normal northwest	Near normal; Below normal west central
The Maritimes and Newfoundland and Labrador	Near normal; Above normal south	Near normal
Yukon, Northwest Territories, Nunavut	Above normal Yukon, NWT & western Nunavut; Near normal eastern Nunavut; Below normal north of Hudson Bay	Near normal; Above normal eastern NWT and western Nunavut Near normal elsewhere

Complete Fall Forecast details, including regional breakdowns, maps and charts are available on our seasonal page at theweathernetwork.com/fall.

For your daily forecasts visit theweathernetwork.com or download The Weather Network App available on iOS and Android and create an account for personalized and up-to-the minute forecasts.