Toronto’s coldest month averages a nightly low of 13.6°F, according to Environment and Climate Change Canada’s 1981-2010 climate normals. That single number sets the terms for this entire guide: how many cords a household burns through the season, and which species actually earn a spot in the wood shed. Here’s how to read that figure and put it to use.
How cold it actually gets here
That 13.6°F figure is not the record low and not a seasonal average. It’s the mean daily minimum for the coldest month, meaning on a typical night in that stretch, the temperature drops to roughly 14°F before sunrise. That’s not an occasional cold snap. It’s the routine, night-after-night baseline that a heating system, wood or otherwise, has to answer for weeks at a time.
A number like that rules out treating firewood as background atmosphere. Below freezing is one thing; a house working against nights near 14°F is another. At that point, wood heat (if it’s doing real work in the home) has to sustain a burn long enough to get through eight or nine hours of darkness without the fire dying and the house cooling with it. That’s the difference between tossing a log on for the mood and loading a stove for the night knowing you won’t be up again until morning.
This is also the figure that decides whether density is a nice-to-have or a requirement. In a place where winter lows stay in the 40s, a lighter wood burns fine, and the inefficiency barely registers. Once nights are routinely near 14°F, every cubic foot of wood in the firebox needs to be pulling its weight, because the house is losing heat faster than a mild climate ever would, and there are more hours of the day when the fire is the only thing standing between comfort and a cold house.
It also changes the math on quantity. A winter that bottoms out this low doesn’t just need “some” firewood stacked by the door. It needs a supply calculated with margin, because a shortfall in February, when the coldest stretch typically lands, is a different problem than running low in a mild April. Readers in warmer parts of the region can treat a woodpile as a supplement. Here, with lows this consistent, wood heat has to be planned like a utility, not a hobby.
None of this means every household is relying on wood as a sole heat source. Plenty of homes here burn wood alongside a furnace, using it to offset heating bills or to keep one room comfortable through the coldest stretch. But the 13.6°F baseline is why that supplemental wood still needs to be dense, dry, and stacked in real volume rather than a decorative armful by the fireplace.
Which woods are worth the effort here
Density is what a cold winter asks for, because a cord is a fixed volume, always 4 feet by 4 feet by 8 feet, or 128 cubic feet, no matter what’s stacked inside it. A dense hardwood packed into that space simply weighs more and carries more stored energy than a lighter wood filling the same footprint. According to Michigan State University Extension, a cord of well-seasoned hardwood delivers roughly 20 million BTU, which the extension compares to about 145 gallons of #2 fuel oil or 215 gallons of LP gas. That average is the baseline every species measures against, up or down, depending on how dense and how dry the wood actually is.
That average also comes with a warning worth repeating: it’s an average. Species and moisture content move the real number a lot in either direction. A cord of dense, properly seasoned hardwood can outperform that figure. A cord of the same species cut too green, or a lighter wood species entirely, can fall well short of it. The number on a chart is only ever a starting point, not a guarantee of what’s actually burning in the stove.
What density buys you on the coldest nights
In a climate with nights near 14°F, the wood that matters most is whatever burns longest and hottest without constant reloading, the wood meant to carry a fire from evening through morning. Lighter, less dense woods have their place too: they’re easier to split, they catch faster, and they’re the right choice for kindling or for shoulder-season fires in October and April when the house doesn’t need an all-night burn. Using a dense hardwood to start a cold stove is a waste of good wood; using a light species to hold heat at 2 a.m. in January is a waste of a night’s sleep.
Availability matters as much as any chart. A species with excellent numbers on paper is worthless if the only supply locally sold has been sitting green in rounds for six weeks. A modest wood that’s genuinely seasoned and available from a local supplier will outperform a theoretically superior species that nobody nearby has had time to dry properly. This site’s dedicated species-by-species guide breaks down individual woods, their comparative density, smoke, and spark behavior in detail; this page’s job is to say that in a winter this cold, that comparison is worth doing before you buy.
| Heat source | Approx. quantity | Heat output |
|---|---|---|
| Seasoned hardwood, one cord (128 cu. ft.) | 1 cord | ~20 million BTU (average) |
| #2 fuel oil | ~145 gallons | ~20 million BTU (equivalent) |
| LP gas | ~215 gallons | ~20 million BTU (equivalent) |
How much wood a winter takes
There’s no honest single number for “cords per winter” that applies to every household, because the answer depends on three things that vary house to house, not region to region. A published figure that ignores those variables is guessing on your behalf, and guessing badly.
- How cold the winter runs: a season that tracks close to that 13.6°F coldest-month average burns through wood faster than a milder one, and a harsher-than-normal winter can push consumption well above what a household budgeted for.
- How well the house holds heat: insulation, air sealing, window quality, and even how many exterior walls a room has all change how much wood it takes to keep that room comfortable through the same outdoor temperature.
- Whether wood is the main heat source or a supplement: a household running a wood stove as its primary heat needs a fundamentally different supply than one burning a fireplace a few evenings a week alongside a working furnace.
The mechanism that makes these variables matter isn’t subtle. A poorly insulated house pushed through a genuinely hard winter can burn double what a tight, well-sealed house uses in that same climate, loading the same number of logs into a stove but losing the resulting heat out drafty windows and thin walls almost as fast as it’s produced. That’s not a wood problem. It’s a house problem that firewood happens to expose.
Run the estimate down that list for your own place before buying a season’s worth of wood. Start with how the past few winters have actually felt in your specific house, not a regional average, then adjust up if you know the insulation is dated or the fireplace is your main heat, and adjust down if wood is strictly supplemental to a furnace that’s doing most of the work. Buying in increments through the season, rather than committing to a full year’s supply in October, gives you room to correct once you see how the woodpile is actually moving.
Drying wood in this climate
Seasoning matters more than which species you buy, and it matters everywhere, but the local climate changes how long the process takes. Michigan State University Extension puts the target plainly: firewood should burn at 20 percent moisture or less, while green wood can sit above 60 percent moisture straight off the tree. That difference isn’t cosmetic. Water inside the wood has to boil off before the wood releases usable heat, and that boiling consumes the very energy a fire is supposed to be producing.
What actually dries wood is air moving through a stack and time passing, not direct sun exposure. A humid summer with a short drying season, which is common in much of this region, slows that process down compared to a drier climate elsewhere. Split, stacked wood with room for airflow between rows will generally reach that 20 percent target after one full summer season, but that’s the outcome of proper stacking, not a guarantee tied to the calendar alone. Wood left in unsplit rounds, or stacked tight with no airflow, can still be wet well past that point regardless of how many months have passed.
Red oak is the documented exception worth knowing before you buy or cut it: MSU notes its cell structure makes it dry more slowly than other hardwoods, so it needs more time than the one-summer rule of thumb that works for faster-drying species.
Tie this back to the 13.6°F baseline and the mistake becomes obvious. Wood cut or bought green in spring for use that same coming winter is, in most cases, not actually ready by the time nights are dropping toward the mid-teens. That’s the single most common local error: assuming a few warm months is enough, then discovering in January that the “seasoned” wood in the shed is still hissing and struggling in the firebox instead of burning clean, right when a cold night needs it to perform.