A Nor'Easter before the first Atlantic Hurricane

A spectacular September sky as departing clouds play with the rising sun over Ile Perrot. The lowering angle of the fall sun allows for some beautiful sunrises and sunsets. (Valley Weather Photo)

Monday is the last official day of summer for 2026. I am still in shock the season is coming to an end, and stubbornly wearing shorts while waking my new pup on 6C mornings. I got to be me. While I absolutely enjoy all four seasons, summer is by far my number one. With that being said, fall arrives, like it or not, at 8:04 pm on Tuesday.

With that we are seeing much cooler nights in Montreal as daylight diminishes, along with an increase in morning dew, which will eventually become frost as we cool even more. The good news is that the weather looks spectacular in Montreal, with strong high pressure slowly drifting over southern Quebec for the entire week ahead.

As far as sensible weather is concerned, expect nothing but sunny, seasonable days and clear, crisp and cool nights. There is even a risk of frost across large portions of the upper Ottawa Valley as well as regions well north of Montreal. Frost advisories have been issued for those locations. Daytime highs will range from 16C (60F) up to 20C (68F) by Friday. Morning lows will be on the chilly side, ranging from 2C (36F) off the island of Montreal, increasing to 5C to 7C (40-45F) across metropolitan regions. 

Weekend Nor'Easter

As high pressure continues to suppress any significant weather well to our south this week, strong low pressure is forecast to develop along the Atlantic coast and move north towards southern New England by Friday night. This will be the first Nor'Easter of the young fall season, oddly occurring before the first hurricane in the Atlantic basin. It is a record-setting year, as our strengthening El Nino continues to put a cap on tropical activity in the Atlantic Ocean. We are still awaiting our first hurricane.

This year will be the latest on record for a hurricane to form, the previous benchmark was Hurricane Gustav on September 11, 2002. So far this year we have had only 6 tropical storms, including the current system, Fay, located 655km southwest of the Azores and weakening.

As far as Montreal is concerned, it appears the weather from next weekends potential storm should remain well south and east of the St. Lawrence Valley. Perhaps a few clouds, sprinkles and a chilly northeast wind on Saturday, but maybe nothing at all. Closer to the system, heavier rain, up to 50mm, strong winds and even some coastal impacts would be possible, but that will depend on the final strength and eventual track of the storm. Stay tuned, it's that time of year again.

Above normal temperatures expected for September

The rain stopped long enough last weekend for thousands of spectators to attend the annual car show in Hawkesbury, Ontario. The weather was perfect with light winds, low humidity, 25C and just a wisp of clouds. The perfect weather resulted in nearly 450 classic cars on display. It was a blessing after a summer where so many outdoor events have been rained out. (Valley Weather Photo)

The weather has been rather mild to start the month of September across southwestern Quebec, with indications that it will remain that way. We are at the start of what is expected to be an historic El Nino event, the warming of the waters in the equatorial Pacific Ocean. Typically this means a very moderate if not warm fall and winter season for Montreal and a large portion of Canada. Looking ahead, we can certainly see signals of milder-than-normal weather well into October for the Montreal region.

Warm high temperatures so far this month have reached the middle 20s. with lows remaining in the middle to upper teens. Warm southwest winds on Thursday have been gusting in excess of 60km/h. The wind managed to keep temperatures up overnight, with a low of 19C (66F) at Trudeau Airport. The normal high and low for early September is 20C (68F) and 10C (50F) respectively. We have not seen that, and shorts and t-shirts remain the clothing of choice.

We have managed some decent rainfall to start the month, with officially 49mm at Trudeau Airport, thanks in part to heavy showers on Wednesday evening that produce close to 30mm in just a few hours. I have recorded 44mm here on Ile Perrot.

High pressure will maintain sunny and mild weather well into the weekend, with the next chance of showers coming late Sunday.

Torrential rain on Labour Day weekend washed away roads, flooded homes and destroyed cars across Cape Breton Island in Nova Scotia. The storm resulted in one fatality and prompted a state of emergency across the region. Over 200mm of rain fell in juts a few hours. (Province of Nova Scotia)

It has been a very expensive summer for Canadians coast to coast, as storms and fires have resulted in billions of dollars in insured losses. The most recent storms in Toronto and Cape Breton, Nova Scotia have only added to the totals. In the Windsor storm, two tornadoes moving southeast for Michigan resulted in significant widespread damage to trees, cars, homes and businesses. The September 2 storm resulted in at least 1000 calls to public works for tree removal, 600 of those deemed urgent. Many fell onto homes and cars. The Toronto storm on September 1st, severely damaged Rogers Stadium, resulting in the cancelation of the AC/DC concert that was scheduled for September 16.

Last weekend, a torrential rainstorm dumped over 200mm (8 inches) on Sydney and parts of Cape Breton in Nova Scotia. Torrents of water washed away roads, damaged homes and resulted in one fatality. The damage from this storm alone will run into the hundreds of millions. With an El Nino fueled fall and winter season forecast, we can expect more of the same, with unusual weather patterns creating the potential for dangerous, damaging storms. 

Labour Day, the unofficial end to summer in Montreal

A tranquil weather moment from the heavens as the clouds part at sunrise this week in Montreal. It has been a challenging summer as far as the weather is concerned from coast to coast, with searing heat for some, drought, fires and floods for others. The increasing strength of the current El Nino is sure to make this fall and winter forecast just as challenging to say the least. (Valley Weather)

Labour Day weekend is upon us, typically the unofficial end to summer. This was more of a reality in my youth, as the weather typically turned cooler much quicker and school rarely started until after the last long weekend of the summer. Things has changed considerably these days as most schools are already back in session, and summer warmth tends to drift well into September and in some cases even early October. 

The weather this weekend looks ideal for outdoor activities. Scattered showers are possible Saturday as a stubborn upper level low remains to our northeast, but the day should not be a washout. Sunday and Monday will feature nothing but sunshine, with daytime highs rising into the middle 20s and overnight lows in the low teens. 

You can definitely feel summer slipping way as the longer nights tend to produce a heavier dew in the mornings, as well as fog in places. Overnight low temperatures can easily find their way into the low teens. The trees are also beginning to respond to the shorted amounts of daylight, which typically begins the leaf changing process, despite how warm it is.

It was Toronto's turn this week to join Montreal and Ottawa in the summer of the flood. A powerful thunderstorm on Wednesday afternoon resulted in close to 140mm of rain falling in less than one hour, flooding residents, highways and underpasses across parts of the city. (Toronto Tourism) 

Toronto's 100 Year Storm

It has been the summer of fire and flood across Canada. You can now add the Greater Toronto Area (GTA) to the growing list of communities impacted by significant flash flooding events. Powerful thunderstorms on moved southeast off Lake Huron Wednesday afternoon, racing across the Toronto and Niagara regions and into western New York.

The storms produced widespread wind, hail and flooding, resulting in significant damage  as well as power outages to more than 150,000 homes and businesses. Wind gusts were observed up to 91km/h at Brantford and 83km/h at Pearson Airport. Major damage was reported at Rogers Stadium. Hail as large as 2.5 to 6.5cm punched out windows in homes and cars in North York. Several motorists had to be rescued after 139mm of rain fell in Caledon, with 133mm at Vaughan. A tornado was reported near Bamberg, northwest of Kitchener.

Severe thunderstorms on Thursday resulted in significant damage across this east Windsor, Ontario neighbourhood. (Photo: @onlocation.tv)

On Thursday another round of strong thunderstorms moved across southeast Michigan into the Essex/Windsor area. The powerful storms and possible tornado tore the roof off at least one home spreading debris across the east Windsor neighbourhood. Large, mature trees were uprooted, many landing on homes and cars or blocking streets. Once again large hail and torrential rain fell as well. The Northern Tornadoes Project out of Western University in London will be investigating the storm dame Friday. They suspect based on radar and reports from neighbouring Detroit, that two tornadoes may have impacted the area between Windsor and Amherstburg.

Welcome to meteorological fall

A developing thunderstorm over the St. Lawrence River off Ile Perrot on Thursday, August 27. Summer 2026 will be remembered across Canada for wildfires, flash floods and tornadoes. In Montreal, our weather seemed constantly unsettled, as if Mother Nature was irritated. (Valley Weather Photo)

Back to school, sunsets before 7pm, my snow clearing contract arrives as well as my tire change reminder for October. It must be September in Montreal!

September 1st marks the start of meteorological fall, statistically summer is behind us. The nights grow longer quickly, we see more dew and fog, and already, there is a hint of colour in the trees that will only increase over the coming days. 

The summer months in Montreal flew by at lightning speed as they often do. It was an odd summer to say the least, warm and humid, but nothing earth shattering as far as extreme heat is concerned. Officially the airport managed only seven 30C days, and only one heatwave during the first week of July. It was a wet summer, with the rain falling in bunches, including the June 20 storm that dumped 50 to 200mm on the parts of the city, mainly the West Island and South Shore. 

The flash flooding from the July across parts of the West Island of Montreal will probably end up being the weather story of the year. 

In terms of temperatures, the summer will end warmer than normal, but not record shattering. The average temperature at Trudeau Airport was 20.5C for June (normal 19.0C), 22.9C for July (normal 21.7C), and 21.1C for August (normal 21.1C).

As mentioned it was a wet summer, with precipitation falling on 10 of the 13 summer weekends since June 1st.

What can expect in September and beyond? An El Nino (the warming of the equatorial Pacific Ocean) is well underway, and expected to become a super El Nino. We have already witnessed the results of this across North America, with an active fire season, along with surpassed heat here in the east. The Atlantic hurricane season has also much quiter than normal to date.

The fall is expected to be warmer-than-normal in Montreal, along with less precipitation. Winter will be challenging. Historically El Nino winters produce warmer temperatures along with less snow, but moisture latent southern systems tend to still produce heavy precipitation to the St. Lawrence Valley. This often results in freezing rain or mixed precipitation for Montreal. The great Ice Storm of 1998 occurred during an El Nino winter. Time will tell

More rain and clouds may cover lunar eclipse in Montreal

A severe warned thunderstorm slides across the West Island on Monday afternoon. (Valley Weather Photo)

It has been a wet August across southern Quebec. Scattered showers and thunderstorms have occurred on 14 of the 25 days to date, with more forecast both Thursday and Friday. As a result, 122.7mm of rain has fallen at Trudeau Airport, again with more in some surrounding communities. Clouds have also resulted in cooler temperatures, with no 30 degree days recorded at Trudeau Airport, and only 4 days above 29C (85F).

Wednesday will be sunny and dry, with warm high temperatures in then upper 20s. Low pressure will travel well north of Montreal, dragging a frontal boundary across the region on Thursday. Clouds along with isolated showers and thunderstorms are forecast, some may be on the strong side.

The moon will turn reddish-orange as the earth passes between it and the sun late Thursday night into the wee hours Friday morning. The partial lunar eclipse will be visible in Montreal, if the weather clears. (NASA)

The clouds Thursday night will likely interfere with the partial lunar eclipse here in Montreal. The full Sturgeon moon will be 96.2 percent covered by the Earth's shadow, as it passes between the sun and moon. The eclipse will begin in Montreal at 9:23 pm Thursday night reaching a peak in the early morning hours Friday at 12:12 am. The eclipse will end at 3:01 am.

Over the weekend low pressure passing to the south of Montreal produced rounds of showers and strong thunderstorms. Around 4pm Sunday afternoon, one of the strongest storms this summer moved across Ile Perrot. The storm produced torrential rain, over 25mm, in less than an hour, thousands of lighting strikes and wind gusts over 70km/h. Some flooding did occur once again on the West island, along with widespread power outages from Dorval to Pointe-Claire.

New severe thunderstorm and tornado warnings for Canada

Lightning strikes from a severe warned thunderstorm in eastern Ontario. (Valley Weather Photo)

Environment and Climate Change Canada (ECCC) along with the Meteorological Service of Canada (MSC) has finally introduced the new polygon warning system across Canada as of this past Monday. The long awaited update follows a similar system that has been used across the United States for over 20 years.

In the past when a severe thunderstorm or tornado warning was issued, it would cover an entire geographically designated watch region, usually related to a County, Regional Municipality or city, as in the case of the Island of Montreal. Very often when a severe thunderstorm warning was issued for Montreal, only a small portion of the city would be impacted, leaving the rest of the population with fair skies. This created significant trust issue with the system.

As someone who has followed the weather for 50 years, this would often leave residents confused, and quickly loosing confidence in the weather office. The real threat here would be that the next time, the warnings could be ignored at terrible cost. As our climate changes across Canada, this type of approach to warnings was badly needed.

A sample of the new polygon thunderstorm warning. Forecasters will be able to precisely target those communities, regions or parts of cities that will be directly impacted by the advancing thunderstorm or tornado. Those warnings will then be pushed out by Alert Ready and the WeatherCan app for only those residents who are in the path of thee storm. (ECCC)

With the new polygon system, forecasters will target areas impacted directly by the approaching storms. The polygons will change quickly as the storms and the threats move along. Thunderstorms and tornadoes are often small in scale and impact very precise regions or neighbourhoods. The hope is that this will regain the public trust in the warning system with fewer "false alarms" being sent out over our cell phones through Alert Ready and on the WeatherCan App. This will also allow forecasters to update and advance the warnings more quickly to those who are in immediate danger from the moving thunderstorm or tornado.

The polygon system will only be used for thunderstorm and tornado warnings. Other weather warnings, and watches will continue to use the current traditional county and municipal alert boundaries.

The Polygon Warning System works!

So on the afternoon of Wednesday, August 12, when severe thunderstorms were impacting primarily extreme eastern Ontario into far western Quebec, Ile Perrot and Vaudreuil-Dorion, those areas were the only regions that received the thunderstorm warnings. The system worked! The storm dumped 25mm (1 inch) of rain at my weather station on Ile Perrot in under 1 hour, while only 1.4mm fell at Trudeau Airport in Dorval during the same period.

Partial solar eclipse visible in Montreal on Wednesday

Skies will be partly cloudy in Montreal on Wednesday for the partial solar eclipse set to start at 12:50PM. The eclipse will only cover 18 percent of the sun in Montreal. (NASA)

If the sun looks a little different through the midday hours in Montreal on Wednesday, that is because it will undergoing a partial solar eclipse. A solar eclipse occurs when the moon moves directly between the earth and the sun. In this case Montreal will be on the western edge of the celestial event, unlike the spectacular total eclipse that occurred over southern Quebec on April 8, 2024.

Nonetheless, they are always exciting moments for weather and space geeks alike. The eclipse in Montreal will begin at 12:50PM, reaching a peak at 1:45PM and ending at 2:38PM. Only 18 percent of the sun will be covered in Montreal, so unless you have a good pair of eclipse glasses, the show will likely go unnoticed by most.

The weather should be ok around that time, however we do have the pesky risk of isolated showers and thunderstorms on Wednesday, as we have had each day this week. Temperatures will be a warm, muggy 27C (81F).

The partial eclipse will be visible through most of eastern Canada and New England. The best location to  view the eclipse in Canada will be across eastern Newfoundland, with St. John's expecting 53 percent coverage.

For totality take to the NASA website, or grab a quick (expensive) plane ticket to Russia, Greenland, Iceland, Portugal or Spain. Those regions will have quite a show later Wednesday as they approach sunset. Madrid is expecting 99 percent coverage, or near totality for the first time since 1999. For Iceland, it will be the first total solar eclipse since 1954.

As with any event involving the sun, you will need special glasses to observe. Unfortunately, I can't find mine from 2024. Damage to your eyes can occur in seconds when you stare directly into the sun. Your best bet, pull up a chair to your computer and stream away safely. Enjoy!