In Quebec, heating season begins in September, based on 30-year climate normals, and demand builds through the fall until it peaks in January. The season stretches across roughly nine months, with the coldest stretch running from December through February, before temperatures climb back above the heating threshold in June.
When the heating season starts in Quebec
Environment and Climate Change Canada counts heating degree days below an 18°C base, the standard used across the country to measure how much a building needs to be warmed to stay comfortable. At the reference station, Montreal/Pierre Elliott Trudeau Intl A, September is the first month where the normal mean daily temperature, 15.5°C, drops below that 18°C line. That’s the mechanical answer to when heating demand starts here: not a date on a calendar, but the month where the 30-year average tips below the threshold.
From there, the degree-day count climbs steadily. It peaks in January, at 862 degree-days, the coldest month in the normals record for this station. The season then runs about nine months in total, with the mean climbing back above 18°C in June, which is when heating degree days effectively disappear from the ledger.
None of this means a homeowner in Longueuil or Trois-Rivières can circle a date on the wall calendar. A monthly normal is a 30-year average. Some years bring a cold snap in late August; other years stay mild well into October. The number tells you the shape of an average winter, not the forecast for this one.
Here’s the monthly breakdown, in heating degree-days below 18°C, for the full year:
| Month | Heating degree-days (below 18°C) |
|---|---|
| January | 862 |
| February | 726 |
| March | 621 |
| April | 348 |
| May | 155 |
| June | 37 |
| July | 6 |
| August | 17 |
| September | 94 |
| October | 296 |
| November | 476 |
| December | 725 |
Every month of the year carries at least a small heating load here, even July and August, which says something about how far north this climate sits compared to much of the continent. The table also shows how sharply the load builds from October onward: November and December already sit close to the January peak, which is a useful reminder for anyone tempted to wait until the first snowfall to think about their furnace or baseboard heaters.
How hard the winter works here
The annual total at this station comes to about 4,363 heating degree-days below 18°C. Degree-days are a rough stand-in for fuel use: a year with twice the degree-days of another, for the same house, tends to burn roughly twice the energy to stay warm. That’s the practical reason this number matters more than any single cold snap.
The monthly table above tells a story the annual figure alone can’t. Quebec’s total comes from a long season rather than a short, violent one. Nine months carry some heating load, and three of them (December, January, February) sit close together near the top of the range. That’s different from a climate where a brutal two-month freeze accounts for most of the year’s total while the rest of the calendar stays mild. Here, the furnace or the baseboards are working, at some level, for the better part of three seasons.
That shape matters for anything from insulation upgrades to how a household budgets for fuel. A long season means small inefficiencies (a drafty window, an underperforming thermostat) get multiplied over many more weeks than in a climate with a short, sharp winter. It also means equipment gets more total run-hours over a year, which is worth keeping in mind when thinking about maintenance schedules later in this guide.
Comparing this number to a heating degree-day figure from south of the border would be misleading. Canadian normals use an 18°C base measured from 1981 to 2010; American figures typically use a 65°F base over 1991 to 2020. The math doesn’t translate cleanly, so the honest move is to leave that comparison alone and judge Quebec’s climate on its own terms.
What most homes in Quebec actually heat with
Statistics Canada’s most recent survey on primary heating systems shows a province where electricity, not gas or oil, dominates the picture:
| Heating system | Share of homes |
|---|---|
| Electric baseboard heaters | 54% |
| Heat pump | 16% |
| Forced-air furnace | 11% |
| Boiler with hot-water or steam radiators | 4% |
| Heating stove | 2% |
More than half of homes in the province rely on electric baseboard heaters as their main system. That share reflects Quebec’s access to relatively inexpensive hydroelectric power over the decades when many of these houses were built, not a judgment on which system performs best today. A share of installed equipment says what was cheap to run when the drywall went up; it says nothing about what would suit a particular house now.
Baseboard heaters have real strengths. They’re simple, there’s no ductwork to leak or maintain, and each room can be controlled somewhat independently since units are often wired to separate thermostats. The tradeoff is that they heat by convection alone, so a room can feel warm at the thermostat while corners near windows or doors stay noticeably cooler. They also do nothing for humidity or air filtration, since there’s no air handler moving air through the house.
The maintenance item that gets skipped most often is simple: dust buildup inside the heating element. A baseboard unit that’s caked with dust and pet hair runs less efficiently and, in a worst case, can pose a fire risk if flammable material sits too close to the unit. Vacuuming the fins with a soft brush attachment once a year, and keeping furniture, curtains, and rugs at least a few inches clear of every unit, is the whole job. It’s cheap, quick, and it’s the one step most households never think to do until something smells wrong.
Run it once before you need it
Heating systems tend to fail on the first genuinely cold night, which is exactly when every technician in the region is already booked solid. The fix is to test the system weeks earlier, sometime in September, before the season’s real demand kicks in. Here’s a sequence that works for most systems, cheapest and quickest steps first:
- Turn the system on for a short cycle, even if the house doesn’t need heat yet, and just listen. Rattling, grinding, or a burning-plastic smell are worth investigating before the cold arrives.
- Expect a faint burnt-dust smell the first time a furnace or baseboard heater fires up after months of sitting idle. That’s normal, dust settling on the elements, and it should clear within a few minutes. A smell that lingers or gets stronger is not normal.
- Replace or clean the furnace filter if the home has a forced-air system. A clogged filter restricts airflow and makes the blower work harder for less heat delivered.
- Clear the space around every vent, radiator, or baseboard unit. Furniture, curtains, and rugs pushed up against a heat source both waste energy and create a fire hazard.
- Test the carbon monoxide alarm. Any fuel-burning appliance, a furnace, a boiler, a wood stove, can produce carbon monoxide if it malfunctions, and a working alarm is the cheapest insurance available against it.
- Call a professional if the system won’t hold a cycle, trips a breaker, or keeps producing an odd smell after the first few runs. That’s a sign of something beyond a seasonal tune-up.
For homes with ductwork, there’s one more thing worth knowing. The U.S. Department of Energy notes that “in a typical house, about 20%-30% of the air that moves through the duct system is lost due to leaks, holes, and poorly connected ducts.” That means a furnace can be running perfectly and still fail to deliver much of its output to the rooms that need it. Since roughly 11% of Quebec homes rely on forced-air furnaces, checking accessible duct joints for gaps or disconnected sections is worth adding to the fall checklist for anyone with that setup. For a deeper look at heating options by fuel type, see our companion guide on wood heating.
What turning it down is actually worth
The U.S. Department of Energy states: “You can save as much as 10% a year on heating and cooling by simply turning your thermostat back 7-10°F for 8 hours a day from its normal setting.” That figure covers heating and cooling combined over a full year, tied to a specific setback range held for a specific number of hours. It isn’t a per-degree rule, and it doesn’t apply to heating costs alone.
For a house in a territory where the heating season runs about nine months, as it does here, that setback has more hours to work with than it would in a climate with a shorter winter. A nightly or workday setback held consistently from September through June adds up across a much longer stretch of the calendar than in places where furnaces only run for a few weeks. The mechanism is the same everywhere; what changes in Quebec is simply how many months that habit gets to compound.