Spectacular fall weather for Montreal and southern Québec

Another spectacular sunrise over Ile Perrot on Thursday morning, in what has been a near-perfect stretch of fall weather across southern Quebec. (Valley Weather)

Montreal and southern Quebec continue to enjoy a long stretch of near-perfect fall weather. It does not get much better than this for October in Montreal. No precipitation has fallen since last Thursday, and with the exception of some clouds along a weak cold front Thursday, we have had nothing but sunshine.

Daytime temperatures have been seasonable, reaching into the low teens, while overnight lows have been cool, dropping very close to the freezing point for many locations. Here on Ile Perrot, we have had frost each of the last few mornings, with the growing season essentially coming to an end now.

The fall colours are also accelerating here in the city with the current dry and cool weather. Most locations are at or past prime, with the leaves beginning to tumble to the ground quickly.

Looking ahead into the upcoming weekend and early next week, we have another strong ridge of high pressure that will arrive Friday, with nothing but sunshine forecast through next Tuesday. Temperatures will be cool, with daytime highs either side of 10C (50F) and morning lows at or slightly below freezing.

Get those snow tires on! Despite our nice weather of late, you know winter is on the way. This was the seen last Thursday north and east of Quebec City as the first snow fell in many parts of the province. (Surete du Quebec)

Behind Thursday afternoons cold front, some gusty north winds will prevail into Friday, adding to the chill in the air. Now is the time to prepare for winter. Mild or not, we will still have snow and ice to deal with as some parts of Quebec have already experienced.

For the second time in less than a month, portions of Highway 12 on the Outer Banks of North Carolina were washed away. Sub-tropical storm Josephine will now bring hurricane force winds to the offshore waters of Atlantic Canada. (OBX Voice)

Sub-Tropical Storm Josephine

The aforementioned area of high pressure is helping to steer sub-tropical storm Josephine east into the open waters of the Atlantic. Josephine formed on Wednesday from what was a strong nor'easter located east of the Outer Banks of North Carolina. The barrier islands have been hammered all week by heavy surf and strong winds. The result has been significant damage to coastal highway 12 as well as some property damage. This is the second storm is less than one month to wash out portions of the highway that connects the fragile barrier islands along the North Carolina coast.

The forecast track of sub-tropical storm Josephine, expected to move south and east of Atlantic Canada through Sunday. (Canadian Hurricane Centre) 

Early Thursday morning Josephine was located 765 kilometres south, southwest of Halifax, with 100km/h winds. The storm was forecast to move northeast at 20km/h, while transitioning into and powerful extratropical low. Josephine will remain south and east of Atlantic Canada, however some clouds, gusty winds and heavy surf are likely for coastal Nova Scotia and Newfoundland, along with a few heavier rain showers and isolated thunderstorms.  

Fall storm followed by the coldest air of the season

Dark, menacing clouds advance on the rising sun this past week on Ile Perrot. It certainly has felt like October all week in Montréal, with chilly temperatures, plenty of rain, drizzle and gusty winds. In terms of fall foliage, many locations in and around Montreal are nearing peak colour this weekend. (Valley Weather)

Strengthening low pressure is forecast to move across Lake Huron and down the St. Lawrence Valley on Friday, bringing with it some steady rainfall and gusty winds. A warm front will lift north towards the United States border on Friday morning, with a period of heavy rain likely ahead of it. Winds will veer to the northeast gusting at times up to 50km/h in Montreal during the morning hours. As the storm system shifts east of the city, winds will back to the southwest and eventually west, gusting up to 60km/h.

In terms of rainfall, we can expect another 15 to 25mm, to go along with our 20 to 40mm that fell on Tuesday. Temperatures will be quite chilly with this fall storm, with Montreal never really get into the warm sector. Expect highs on Friday near 9C (49F), dropping steadily behind the cold front to the freezing point by Saturday morning.

Some regions across central and northwest Quebec can even expect some snow on the backside of the low pressure, with as much as 10cm forecast for Chibougamau and the Saguenay region. Some flurries may even spread across the upper elevations of the Eastern Townships and Green Mountains into Saturday morning.

Saturday will be a breezy, cold day, with partial clearing and temperatures holding in the single digits. Saturday night may be the coldest of the fall so far, with lows expected below freezing for most locations, along with widespread frost, 0C to -2C for Montreal.

High pressure will build into the region on Sunday, with warming temperatures expected through Thursday, along with an extended period of dry weather. Highs will range from the lower teens Sunday to the middle and even upper teens by Thursday.

Stormy weather week for southern Quebec

The first frost of the season occurred on Saturday morning here on Ile Perrot. It was very light, with temperatures dropping to 1C (33F). A much colder airmass arrives by next weekend, with widespread frost, freezing temperatures and even some snow possible. (Valley Weather)

Heavy Rainfall Warning for Montreal for Tuesday.

October can be an interesting weather month, like April, with the seasons in full battle mode. Over the weekend, we had a major hurricane in the Pacific Ocean off the coast of Mexico, as well as one impacting the Gulf Coast. The first snow of the season fell across portions of southern Alberta and Saskatchewan, and the remains of hurricane Rachel brought pounding surf and significant flash flood from California into Nevada.

In Montreal, Saturday was as nice a fall day as you can have, with widespread sunshine, light winds and seasonable highs in the teens. The good weather for Montreal has come to an end as clouds and showers are moving in along a weak cold front late Monday. 

That front will stall to our south over northern New England, and may even slowly move north as a warm front Tuesday afternoon. Low pressure will move along the front, tapping into moisture from the remains of Pacific hurricane Rachel. Steady rain and thunderstorms are expected Tuesday, with as much as 40-60mm from Montreal south to the United States border and eastward into the Townships.

The showers may persist into Wednesday morning. The mild temperatures Monday, will be replaced by much cooler highs in the single digits Tuesday on gusty northeast winds up to 50km/h.

Some clearing is possible on Thursday before another, even stronger fall storm approaches southern Quebec by Friday. This storm will produce heavy rain and strong winds, followed by very cold temperatures Saturday and even some snowfall across parts of southern Quebec and New England. Expect a widespread frost and freezing temperatures, even in urban areas by Sunday morning.

Hurricane Isaias made landfall around 8pm Friday night near Destin, Florida. Very strong wind gusts, in excess of 100mph (160km/h), resulted in widespread damage and power outages along the Florida Gulf Coast. Many homes lost there roofs, like the one above in Pensacola Beach. (Weather Nation)

Hurricane Isaias

Hurricane Isaias made landfall near Destin, Florida on Friday evening, resulting is significant wind damage and flooding. The hardest hit areas were across the western Florida panhandle from Pensacola west towards the Alabama border. Winds gusted over 100mph, producing significant structural damage and knocking power out to nearly one million residents across parts of Florida, Alabama, Mississippi and Georgia. 

Four deaths were blamed on the once Category 3 storm, the first hurricane in the Atlantic basin in 2026. Isaias weakened rapidly after landfall, but still had enough punch to spread heavy rain, thunderstorms and isolated tornadoes north into the Carolinas and Middle Atlantic region. 

October thunderstorms rattle around southern Quebec - Isaias first hurricane of 2026

The third thunderstorm in less-than 12 hours moved across the region early Thursday morning. The storms produced lots of lightning but no severe weather was reported. They were fast moving, resulting in just 5-10mm of rain on average across the Montreal area. (Valley Weather)

Several rounds of thunderstorms crossed the Montreal region over the last 24 hours. That included some rare nocturnal October storms just after midnight, that put on quite a sound and light show. The storms were fast moving, and outside of some vivid lightning and gusty winds, only 5-10mm of rain fell. Lightning strikes did manage to shut down the weather weary REM commuter trains to the south shore for several hours Thursday morning.

Just enough instability in the atmosphere will be present again Friday afternoon for perhaps another isolated, non-severe storm. Small hail and gusty winds will be possible. Otherwise high pressure will build into the region for Saturday and most of Sunday, resulting in fair skies. 

Temperatures will start the forecast cycle chilly, only reaching 13C (55F) Friday after morning lows near 5C (41). We can expect warmer highs both Saturday and Sunday as southerly winds develop between a Bermuda high off the Atlantic coast, and the remnants of hurricane Isaias moving north from the Gulf of Mexico into the Ohio Valley. The warm south winds will push highs close to 20C (68F) in Montreal.

By Sunday night and into Thanksgiving Day, clouds and perhaps a few showers will begin moving north across New England and into southern Quebec from what is left of Isaias.

NOAA image of Hurricane Isaias in the southern Gulf of Mexico late Thursday.

Hurricane Isaias

It has been a record-breaking quite hurricane season in the Atlantic basin to date, with only nine named storms and the latest we have had to wait for a hurricane to form. That record was set way back on October 7, 1905. It took until 7pm Wednesday evening for the first hurricane of the season in the Atlantic. Meanwhile the Pacific has recorded 19 storms, 9 of which have become hurricanes, 6 major storms, category 3 higher. The El Nino fueled Pacific hurricane season has resulted in over $682 million dollars in damage and 18 deaths.

Back to Isaias, as of Thursday evening the center of the strengthening storm was located in the Gulf of Mexico, 525 km south of the Mississippi River. The storm was moving northeast at 19km/h, with 160km/h winds, a category 2 hurricane. Isaias has prompted hurricane warnings along the Gulf coast from Florida to Mississippi. The storm should make landfall late Friday or in the pre-dawn hours Saturday, with a storm surge of 5-7 feet above sea level along the immediate coast.

Heavy rain, in excess of 150mm, will spread inland across the southeastern United States, north into the Ohio Valley.

That four-letter word is back across parts of Quebec - SNOW!

The calm after the storm on Friday, October 2. Morning rain and gusty winds gave way to a spectacular sky by day's end. (ValleyWeather)

A strong cold front has cut across the province early Monday morning, ushering in the coldest airmass of the season so far, on gusty northwest winds. High temperatures have been reached already, around 13C (55F), with the mercury expected to fall into the single digits, as low as 5C (41F) by Tuesday morning for Montreal. Along with the chilly air will be northwest winds in the 30-50km/h range. Parts of the province north of Montreal, including the higher elevations of the northern Laurentians may see the first snowflakes of the year, as well as the mountain peaks towards the Vermont border.

Don't panic just yet in Montreal, but now is the time to plan. I have my winter tire appointment booked already at Gordons in NDG, no point in avoiding the inevitable.  There is often a sharp contrast from September into October across Quebec and Ontario. September for the most part is just another summer month now. Weather conditions change rather abruptly in October, with the average high dropping from 16C (61F) at the start of the month, down to 9C (49F) by Halloween. Average lows drop to near the freezing point by months end.

More construction in Montreal as this ghoulish crew assembles a Halloween display on Ile Perrot. October weather is in sharp contrast to September, with frost, northwest winds and usually our first snowflake or two occurring. Time will tell what a Super El Nino October has in store for Montreal. (ValleyWeather)

This past September was not unusually warm, but we still managed an average temperature of 16.6C, which was 0.6 degrees above normal at Trudeau Airport in Montreal. September was very dry across the province of Quebec, with many regions running significant moisture deficits. Montreal measured only 50.6mm of rain, most of that falling on September 8-9. The long-term average is 89.2mm.

Montreal can expect a variable week, blustery and chilly to start, a brief warm up midweek, followed my clouds and cooler temperatures by Friday. Typical October weather for southern Quebec, with a vibrant mix of sun and clouds against the backdrop of vivid foliage that is starting to spread quickly. 

Clouds and showers are possible midweek, but no major weather systems are expected. The gusty northwest winds will likely prevent frost from forming in Montreal on Monday and Tuesday, but regions northwest of the city may see frost Tuesday morning.

Montreal remains on northwest edge of powerful Nor'Easter

A powerful Nor'Easter resembling a hurricane meanders off the east coast of the United States over the weekend. The storm produced widespread coastal flooding and damage from New England to North Carolina. (NOAA)

A powerful coastal storm has pushed clouds and showers into Montreal early Monday morning. The storm has been meandering off the eastern coast of the United States, hammering the region with high surf, strong winds and heavy rain. The coastal impacts have been significant, with widespread damage and flooding reported. Power is out to over 30,000 homes and businesses across the middle Atlantic and New England. Several regions including coastal New Jersey, Long Island and Hatteras Island, North Carolina have declared local states of emergency.

Ocean over wash across Highway 12 on Hatteras Island in North Carolina. Pounding surf over several days eroded the dune line an washed over the coastal highway. (NCDOT)

Successive high tides over the weekend, combined with pounding surf and winds over tropical storm strength, inundated coastal homes and roads. Highway 12 on the Outer Banks of North Carolina was washed out resulting in thousands of tourists being stranded. Emergency ferry service has been established, but the process is slow.

Here in the St. Lawrence Valley, we are seeing waves of light precipitation Monday morning, pinwheeling around strong low pressure located along the New Jersey coast. Monday will be a showery, chilly day in Montreal, with continued northeast winds, gusting up to 50km/h and a high of 16C (60F). Those winds pushed over 60km/h in parts of the region on Sunday, as we remained fully in the broad circulation of the east coast storm.

High pressure will settle into southern Quebec on Tuesday, accompanied by clearing skies. Temperatures will remain above normal in Montreal for most of the upcoming week.

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.