Spectacular fall weather for Montreal - no rain in sight

A rocky beach along the shoreline of Lac St. Louis in Lachine. Water levels across the region remain at near-record low levels. The area will be getting an increase in water on October 18, with a planned increase in flow from the Moses-Saunders Power Dam in Cornwall, Ontario. The dam is operated by International Joint Commission and the Saint Lawrence Seaway. The flow will be increased over a 36 hour period, raising Lac St. Louis by as much as 15cm (6 inches).  (Valley Weather Photo)

September weather does not get any better than this in southern Quebec. However is does come at a cost, as drought conditions continue to worsen across the region. Starting with the upcoming forecast, we can expect nothing but sunshine through next Sunday. A dry cold front on Tuesday will result in gusty winds, up to 40km/h and a drop in temperatures, but no precipitation. 

The weekend was warm and dry in Montreal, with a well-above normal high of 24.9C (77F) on Sunday. Monday will be warm as well, reaching the middle 20s for highs. Overnight lows will be seasonably cool, around 10C (50F). The balance of the week will be slightly cooler, around 19C (66F) for highs and morning lows in the single digits. There will be a risk of frost on Wednesday and Thursday mornings.

By late week, strong high pressure will shift to our southeast, deflecting any storms away from out region. Temperatures will be on the rise again, with near-record warmth expected for the first weekend in October. There is no rain in sight. Montreal remains at 33mm for September, well below normal, and just above the record of 27mm set in 1961.

Saint Lawrence River International Joint Commission to raise water levels for Lac St Louis

The International Joint Commission will be increasing the flow from the Moses-Saunders Power Dam near Cornwall, Ontario on October 18. This is in response to the near-record low water levels on Lac St. Louis in the Montréal region. The last time this was required was back in the fall of 2012. Water levels are dangerously low in our region, with some areas to low for watercraft navigation. 

Water levels currently sit at around 67.88 feet on Lac St. Louis. The increase in flow on October 18, will bring the level of the lake up to approximately 68.24 feet. The increase in flow will only be for a 36 hour-period to help facilitate the seasonal removal of watercraft in our region. Many parts of southwestern Quebec and eastern Ontario remain in moderate to severe drought conditions.

Another extended period of dry weather for southern Quebec

A rare sight this September, as clouds and showers occurred in Montréal on two days this past week. Unfortunately amounts were light, with less than 10mm of rain falling at most locations. This is not nearly enough to bust the drought conditions prevailing across a wide swath of our region. (Valley Weather Photo)

Despite the rainfall this week, conditions remain exceptionally dry across southern Quebec. On Thursday, low pressure travelled south of our region, keeping the heaviest rainfall and thunderstorms across New York and parts of Ontario.

At Trudeau Airport a meager 3.9mm of rain fell Thursday, barely enough to wet the soil. That brings this weeks total to 9mm, again not nearly enough to break the drought conditions. The monthly total sits at only 28.4mm, well-below the long-term average of 89.2mm for September.

The dry conditions have resulted in a n early apple season across the region. The fruit is ready to be picked and is showing signs of stress from lack of moisture. The apples are starting to fall from the trees. Water levels as mentioned in previous posts, remain dangerously low. Be vigilant if boating on the St. Lawrence or Ottawa Rivers and tributaries.

After a few isolated showers Friday, the balance of the month into early October looks warm and dry. Expect daytime highs in the 20s, with overnight lows in the teens. A dry cold front Tuesday will result in cooler temperatures and perhaps some frost by the middle portion of next week. As far as precipitation is concerned, no rain is forecast until perhaps the second week of October.

Canadian Hurricane Centre forecast track of Hurricane Humberto, which should remain off the coast in the open waters of the Atlantic, but will bear watching for any impacts to Atlantic Canada. Meanwhile a tropical system may develop between Humberto and the US east coast. If it forms it would be named Imelda, and may produce heavy rain and high surf for the US coast. (CHC)

Strong high pressure will set up over Quebec deflecting any storms well to our south. This includes any tropical systems. The Atlantic has become active again, with Hurricane Humberto located 750km northeast of the Leeward Islands early Friday morning. Humberto is forecast to become a major hurricane this weekend, while remaining over the open waters of the Atlantic Ocean. 

Of more immediate concern is an area of low pressure south of the Bahamas that is forecast to become a tropical system this weekend. This storm is forecast to strengthen and pose a threat to the US southeast coast from Georgia to North Carolina early next week. More details this weekend as the storm further develops.

Some rainfall this week - however drought conditions persist across southern Québec

The last summer sunrise for 2025 over Montreal early Monday morning. Fall officially arrives at 2:19 pm Monday afternoon, September 22. The week ahead will not feel fall-like at all, with above normal temperatures expected to persist into the start of October. (Valley Weather Photo)

A weakening frontal boundary to the west of Montreal, may produce a few showers Monday morning, with a better chance late in the day, and perhaps even a rumble or two of thunder. Any rain will be welcome. Drought conditions are deepening across eastern Canada and New England. In Montreal, Sunday was our 14th day in a row with no precipitation. The monthly total stands 21.4mm, most of that falling in a single thunderstorm on September 4th. The normal precipitation for September is 89.2mm at Trudeau Airport. 

The North American Drought Monitor is reporting moderate to severe drought conditions (D-1, D-2) across large portions of southern and eastern Ontario and southern Quebec. Drought conditions then spread south and east across New England and southern Quebec. As a result, water levels remain dangerously low is several parts of the Great Lakes, Ottawa and St. Lawrence River watersheds including adjacent rivers and streams.

Vaudreuil Bay on Sunday afternoon, looking northeast towards the Island of Montreal. Water levels remain extremely low on both the Ottawa and St. Lawrence Rivers, with many docks sitting high and dry and rocky beaches where water should be.

The outlook for the week is a little more promising, but we are not seeing any drought busting rainfall. Several weak systems will produce scattered rain showers, resulting in perhaps 20mm or so by the end of the week, Any moisture is welcome.

The Autumnal Equinox occurs on Monday afternoon at 2:19PM. Despite a couple of cool mornings this past weekend, with even a hint of frost in many regions outside Montreal, warmer weather will prevail this week. Overnight lows dropped into the low single digits Sunday morning in the Montreal region, with even a few spots in the Eastern Townships below freezing. Sherbrooke reported a low of -3C (27F) Saturday morning and -2C (29F) on Sunday morning. Many locations reported frost and even a hard freeze ending the growing season for some.

High temperatures rebounded quickly into the low to middle 20s Sunday afternoon, with light winds and bright sunshine, a perfect final day of summer. This week will continue the trend of above normal temperatures, with highs in the low to even middle 20s and lows in the middle teens.

Very dry weather conditions continue across southern Quebec - frost possible

The trees are starting to show signs of colour as we enter the last weekend of astronomical summer. The Autumnal Equinox occurs on Monday, September 22 at 2:19PM.

The first frost of the season is possible this weekend across portions of our region, especially away from metro areas and bodies of water.

Rain has been at a premium this September, with warm and dry conditions prevailing across most of Ontario and Quebec, eastward into Atlantic Canada, as well as adjacent portions New England. According to the Canadian Drought Monitor, nearly 71 percent of Canada is abnormally dry this September, with some of the worst conditions across eastern Canada. Atlantic Canada has reported one of the driest summers on record, with widespread drought, crop failures, wildfires and water shortages.

Here in Montreal, water levels are very low on all area waterways with many municipalities encouraging water conservation. Boating could be a dangerous endeavor, with rocks and debris appear in many spots as water levels continue to drop. One example of low water levels is Lac St-Louis at Pointe Claire, where the current level is at 20.68 metres (67.8 feet), close to the record low of 20.64 metres (67.7 feet) for the date. The average level is around 21.2 metres (69.5 feet) for September.

In June, only 22mm of rain fell at Trudeau Airport, that was followed by 133mm in July, however most of that fell in a single thunderstorm. August saw a return to dry and hot conditions, with only 67.1mm reported, again most of that falling on one or two days. September has been the driest month yet this summer, with only 19.4mm to date. The bulk of that fell in just a few hours on September 4. We have had only a trace of rain since then.

We need rain! This map above prepared by Agriculture Canada shows a significant departure from normal rainfall across most of the country, as much as 200 percent below normal in eastern Canada. This trend has been persistent all summer.

The forecast is not encouraging either as we head into the upcoming weekend. Strong high pressure has dominated our weather this week in southern Quebec. Temperatures have been above normal, with no precipitation. A weak cold front Thursday afternoon may produce a widely isolated shower or thunderstorm, but the chance is low and they will be scattered. The cold front will introduce a wind shift along with cooler temperatures for Friday. The high Thursday will be a summery 27C (81F), dropping to around 10C (50F) overnight and into the upper teens for Friday into the weekend. Some locations outside of metro Montreal do have a risk of frost Saturday night.

An upper level low and a frontal boundary will try to increase the coverage of showers early next week, but at this time amounts look too low to make a dent in the drought.

For the time being, conserve water, be vigilant if boating on area waterways, and be extremely careful with any outdoor burning.

Another stretch of dry weather ahead for southern Quebec

The Suburban, along with Tanguay, held our second annual Family and Pet Day in Cote St-Luc on Sunday. This was a rain date from August 24, when the threat for thunderstorms made it unsafe. Thankfully for the many in attendance, the rain held off this time, with the exception of a few menacing black clouds and gusty winds, along with an isolated sprinkle or two. (Valley Weather)

Strong high pressure has settled into southern Quebec on Monday morning, and will slowly drift southeast over the course of the upcoming week. This will result in another stretch of sunny and dry weather for our region. Temperatures have started off cool Monday morning, with many locations in the single digits, including 9C (48F) at Trudeau Airport. 

Montreal will warm to near 20C (68F) Monday and well into the middle 20's for the balance of the work week, with nothing but sunshine expected. The overnight period will feature clear skies, and cool temperatures, either side of 10C (50F).

The lack of precipitation this summer has resulted in drought conditions across many parts of southern Quebec, especially in the eastern portion of the province as well as Ontario and Atlantic Canada. (ECCC)

The next chance for rain will not come before the upcoming weekend. While the pleasant late summer weather is welcome by many, the area remains excessively dry. Large portions of Canada are actually in one stage or another of drought. In August, most of Quebec had below normal precipitation, with the deficit ranging from 25 to as much as 100 percent below the long-term average. The rain that has fallen in Montreal has often been too much at once, with too many days in between events.

We did manage a few millimetres of rain over the weekend, bringing Montreal up to 21.4mm for the month, but that amount remains below the long-term average to date for September. Southern Quebec needs a slow, soaking rain. Nothing is on the horizon at this point.

Strong winds cut power to over 70,000 homes across southern Quebec

Hydro-Quebec crews are on the ground Friday morning, repairing damage caused by a gusty cold front that moved across southern Quebec late Thursday. At the height of the outages, more than 70,000 customers were in the dark. That number is down to just under 40,000 Friday morning. (Hydro-Quebec)

A fast moving cold front generated strong winds late Thursday afternoon, cutting power to over 70,000 Hydro-Quebec customers across the southern part of the province. This included close to 4400 in the Montreal region. Hardest hit were the Laurentians and Monteregie regions. Early Friday morning, just under 40,000 customers remained without power. A majority of the outages were caused by downed tree branches coming in contact with wires and transformers.

The strong late-summer cold front dropped temperatures from a daytime high of 29C (85F) in Montreal, down into the upper teens in a matter of minutes around 5pm. A few heavier showers and embedded thunderstorms produced a gust front, with winds briefly in the 60-100km/h range locally. Officially at Trudeau Airport, the wind gusted to 63km/h. There were no weather warnings in effect at the time of for the front. Some much need rain fell as well, with 17.8mm recorded at Trudeau Airport, while I measured 11mm at my home on Ile Perrot.

We can expect a calm, sunny Friday, with a warm high near 24C (76F). Winds will increase during the afternoon hours once again, gusting between 20-50km/h. On Saturday, an upper level low will drift over the region, with a cool, breezy and showery day expected, the high will only be 17C (63F). Sunday at this time looks fair, with some cloudy periods and perhaps an isolated afternoon sprinkle or two. The high will be 20C (68F).

Welcome to Meteorological Fall

September skies can be spectacular as Summer begins to give way to Fall. This vivid rainbow developed late Tuesday afternoon after some isolated showers and thunderstorms moved across Ile Perrot and the West Island of Montreal. (Photo: Valley Weather)

Well fall arrived September 1st, at least according to the meteorological community, astronomical autumn will catch up on the 22. September has started off warm, with well-above normal temperatures since Labour Day Monday. Clouds are on the increase as I write, with a strong cold front to our west. While Montreal is at 23C (73F) as of 10:30AM, Toronto, behind the fall-like front, is down to 12C (54F).

The front will produce some gusty southwest winds today, up to 50km/h, along with some thunderstorm activity later this afternoon. A period of steady rain Thursday evening, will taper off by morning, with a fair and warm day forecast Friday.

The cooler air will eventually arrive in Montreal, but it may take a day or so. Another slow moving cold front and upper level low will bring us showers and thunderstorms Saturday. On Saturday, the core of the colder air will arrive, along with showers and a high of only 17C (63F). Sunday into early next week will feature cool nights, with seasonable days along with fair weather through Wednesday.

Our hot and dry summer is now in the record books. In June, only 22mm of rain fell at Trudeau Airport. That was followed by 133.1mm in July, but most of that fell in a few hours on the 13th. August was the hottest month this summer, with 7 days over 30C (86F), including a 6 day heatwave, and the warmest temperature this summer for Montreal,  35.1C (95F). The heatwave included 3 record highs. Montreal managed 70mm of rain, but most of that fell during the last few days of the month. In fact, only 7 days has measurable rainfall at Trudeau Airport.

September heralds the change of seasons. The skies can be dynamic as one season yields to the next. Indications are we can expect temperatures and precipitation fairly close to normal. We will lose nearly 90 minutes of daylight in Montreal from the start to the end of the month. The trees are already showing signs of colour. The fall foliage may be greatly diminished this fall, as many trees are showing signs of heat stress, which can limit the colours.