Updated October 19, 2026
What to look for on the sidewall
The mark that matters is the three-peak mountain snowflake, often shortened to 3PMSF. It means the tire passed a severe-snow test. Mud-and-snow lettering (M+S) is not the same thing, and plenty of all-season tires carry M+S without behaving like a winter tire on March Road or Eagleson at dawn.
Buy the set as four matching tires. A pair of winters on the drive wheels and all-seasons on the other axle is how a car swaps ends when the rear, or the front, finds ice first. Highway 417 makes that mismatch obvious in a lane change.
Ottawa's rule, and Quebec's
Ontario does not mandate winter tires. Ontario's winter driving page says all-season tires can start to lose grip at 7°C, and it treats winter tires as the practical choice rather than a legal one. There is no December deadline on an Ontario plate.
Quebec is different, and Kanata drivers hit that difference on the Champlain Bridge. Quebec's winter tire requirements require a winter tire from December 1 through March 15 for vehicles registered in Quebec, including rentals. Vehicles registered outside Quebec are not covered by that rule. An Ontario car can legally cross into Gatineau on all-seasons. The ice on that crossing does not care about the plate.
A useful Kanata set
- A 3PMSF winter tire, the same model and size, on all four wheels.
- Enough tread for slush. Snow performance falls off well before the legal minimum. See when to replace a tire before winter.
- A second set of wheels if you change tires every October. Steel is the usual winter choice because of Ottawa road salt.
- The size on the door placard, or a close match you have compared in the tire size calculator.
All-weather tires that also carry the snowflake are a different product. They can stay on all year. How they compare with a dedicated winter set is covered in all-weather versus winter tires.
Questions
Are winter tires required in Kanata?
No. Ontario does not require winter tires. They are still the right tire once October mornings stay near 7°C.
Do I need winter tires to drive from Kanata into Gatineau?
Quebec's December 1 to March 15 winter-tire rule applies to vehicles registered in Quebec, not to an Ontario-plated car. The roads on that trip are still winter roads.
Is M+S the same as a winter tire?
No. M+S is a tread description. The three-peak mountain snowflake is the severe-snow mark to look for.
Can I put winter tires on only the front or only the rear?
No. Use four matching winter tires. Two winters and two all-seasons leave one axle with less grip on ice.
When should the winter set go on?
When Ottawa morning temperatures stay near 7°C, commonly the second half of October. The changeover timing is covered in the Ottawa tire changeover guide.