Ontario Winter Tires: Rules, Discounts & Timing

Are winter tires mandatory in Ontario? It’s the October question, and the answer surprises people: no. Ontario has no winter tire law. But that doesn’t mean there are no rules worth knowing — the province forces insurers to reward you for installing them, a temperature threshold beats any calendar date, and a mountain-and-snowflake sidewall symbol decides what counts.

What the law actually says in Ontario

Ontario law doesn’t require winter tires on passenger vehicles, full stop. The province recommends them — run four, never mix types — but no fine exists for skipping them.

The rest of the country is stricter. Quebec has required winter tires on vehicles registered there since 2008, from December 1 through March 15, with $200 to $300 fines for non-compliance. British Columbia mandates winter tires or chains on designated mountain highways from October 1 to April 30, with a $121 ticket for ignoring the signs.

So in Ontario the choice is yours. What the province does regulate is what that choice does to your insurance bill.

The discount Ontario actually forces: your insurance

Since January 1, 2016, every auto insurer in Ontario has had to offer a discount to drivers who install winter tires — the only province that mandates it. The law requires the discount to exist; the insurer sets the size. Most land between 3% and 5% of the premium, which on a typical Ontario policy works out to roughly $70 to $125 a year.

To qualify, insurers typically want:

• Four matching tires — same type, size, and tread; no mixing two winters with two all-seasons
• The mountain snowflake symbol on the sidewall (more below)
• A calendar window — most policies want the tires on by early November and left on through March or April

It isn’t automatic, either. You often have to ask at renewal, and some insurers want proof such as a receipt or a declaration of installation dates. Ran winters last season without mentioning it? You may be leaving money on the table.

Swap by temperature, not by the calendar

October 15? November 1? First snowfall? Ignore the dates — the number that matters is 7°C.

Below about 7°C, the rubber in all-season and summer tires stiffens and loses grip, even on bare dry pavement. Winter tires use compounds that stay flexible far below freezing, plus tread crowded with tiny sipes that bite into snow and slush. Transport Canada builds its guidance around this threshold: below it, summer-oriented rubber is out of its comfort zone.

Southern Ontario usually hits that in late October; the north, weeks earlier. The logic reverses in spring: once highs hold above 7°C, winter tires wear and stop poorly, so off they come.

Your insurer cares about the calendar; your tires care about the thermometer. Book early — shops get slammed the weekend of the first snow.

Winter, all-weather, or all-season: what counts

Three categories — the sidewall tells you which is which:

• All-season — the factory default. The name oversells it: really a three-season tire whose compound hardens in the cold. No snowflake symbol, no discount.
• All-weather — a genuine year-round tire carrying the three-peak mountain snowflake (3PMSF) symbol, meaning it passed the industry snow-traction test. Capable in a real Ontario winter and quieter and longer-wearing than a dedicated winter tire, but a compromise on ice and in deep snow.
• Dedicated winter — softest compound, most aggressive tread, best ice and snow performance by a wide margin. Wears fast and feels squishy on warm pavement, which is why it comes off in April.

For the insurance discount, 3PMSF is the dividing line — that’s what insurers mean by “winter-rated.” Confirm with yours whether an all-weather tire qualifies or they expect a dedicated set before counting the savings.

Where your tires spend the summer

Storage decides whether a set lasts four winters or eight:

1. Wash them. Salt and brake dust degrade rubber over months of contact. Soap, rinse, dry fully.
2. Bag them. Opaque airtight bags (or heavy plastic wrap) block UV and ozone, the two things that crack rubber in storage.
3. Mind the position. Tires on rims stack flat or hang on a rack — never stood on a sidewall for months. Bare tires store best upright.
4. Pick the spot. Cool, dry, dark, away from furnaces and motors that pump out heat and ozone.

While they’re off the car, check tread depth. Transport Canada says tires worn close to 4 mm (5/32”) lose their snow grip — if yours are near that mark at swap time, budget for replacements rather than finding out in the first January storm.

A simple Ontario timeline

When	What to do
Early October	Book the swap before the rush; ask about the insurance discount
Late October / by Nov 1	Winter tires on — 7°C rule plus most insurer deadlines
December – March	Drive; check pressure monthly — cold drops tire pressure
April	Tires off once temperatures hold above 7°C
May – September	Clean, bag, and store; shop early if you need a new set

The swapover is also the natural moment for rotation, balancing, and alignment — see our tire rotation and alignment guide. The 100,000 km service checklist covers what else fits the same visit, and our dealership vs. independent shop comparison lays out where to book. You can also find local changeover shops through Mecano’s community site.

Frequently asked questions

Is it illegal to drive in Ontario without winter tires? No. Ontario has no law requiring winter tires on passenger vehicles. Only Quebec mandates them province-wide (December 1 to March 15), and British Columbia requires them on certain signed mountain highways. Ontario instead requires insurers to offer a discount if you do install them.

How much is the Ontario winter tire insurance discount? Ontario law requires every auto insurer to offer a winter tire discount, but the size is the insurer’s choice — typically 3% to 5% off your premium. On a typical premium, that’s roughly $70 to $125 a year. You usually need four tires carrying the three-peak mountain snowflake symbol, installed by the date your policy specifies.

Do all-weather tires qualify for the winter tire discount? Usually yes, as long as they carry the three-peak mountain snowflake symbol and your insurer counts them as winter-rated. Because all-weather tires stay on the car year-round, some insurers still want confirmation of the symbol rather than installation dates. Check with your broker before assuming you qualify.

When should I put winter tires on in Ontario? Swap when temperatures consistently sit at or below 7°C, which in most of Ontario means late October to early November — before the first snowfall, not after. If you want the insurance discount, most insurers expect the tires on by around November 1 and left on through March or April.

Can I run just two winter tires to save money? No. Transport Canada advises installing winter tires in sets of four with matching type, size, and tread, because mixing types makes a vehicle less stable in emergencies. If you must mix old and new for any reason, the deeper tread goes on the rear axle to keep the back end from stepping out.

Is it okay to leave winter tires on all year in Ontario? It is legal, but it is a bad trade. Winter tire rubber wears quickly and feels vague on warm pavement, so you will burn through a set that should last several winters. Running them in summer can also conflict with insurer requirements and quietly cancel your discount.

Sources & further reading

• Transport Canada — Using winter tires
• Ontario Newsroom — Drivers with winter tires eligible for insurance discount
• Ratehub.ca — Do winter tires save money on car insurance in Canada?
• Québec.ca — Requirements for winter tires
• Canada Drives — All-season vs. all-weather vs. winter tires
• Michelin Canada — How do I store my tires?
• Master Mechanic — When to take winter tires off (and when to put them on)