Guide
When to put winter tires on
The short answer: when mornings stay below about 7 °C, or by your legal or insurance deadline, whichever comes first. Book the appointment a few weeks before, because shops fill up at the first snow.
The 7 °C rule
All-season and summer rubber starts to stiffen and lose grip at around 7 °C. Winter tires use a softer compound and deeper sipes that stay flexible in the cold, so they stop shorter on cold, dry pavement as well as on snow and ice. CAA suggests switching once temperatures drop below 7 °C, even if that's before your insurer's date.
One cold morning isn't the signal. Watch for a run of mornings below 7 °C. That's the rule Lugnut uses: it checks the 6 a.m. forecast for your city and tells you when mornings are set to stay under 7 °C for three days.
Legal deadlines
| Where | Rule | Dates |
|---|---|---|
| Quebec | Winter tires required on all Quebec-registered passenger vehicles. Look for the mountain-and-snowflake symbol; M+S alone doesn't count. | December 1 to March 15 |
| British Columbia | Winter tires (mountain and snowflake, or M+S with at least 3.5 mm of tread) or chains on designated, signed highways. | October 1 to April 30 on most routes (some end March 31) |
| Other provinces | No legal requirement. See your insurer's dates below. | — |
Rules can change; check your province's transportation ministry. Our winter tire laws guide covers every province, including studded tire dates.
Ontario: insurance discount dates
Ontario insurers have had to offer a winter tire discount since January 1, 2016, typically up to about 5%. There's no single date: each insurer sets its own window. A review of 11 Ontario insurers by The Globe and Mail found most required winter tires by November 1, a few by mid- or late November, and some by December 1. Most want four tires with the mountain-and-snowflake symbol. Check your policy for your exact dates.
When to take them off
Swap back once mornings stay above about 7 °C, usually April in most of Canada. Winter tires wear quickly on warm pavement. Quebec's requirement ends March 15, but March snow is common, so many drivers wait. B.C.'s highway rule runs to April 30 on most routes.
Before you book the swap
- Check the tread. Winter tires lose much of their snow grip as they wear; many shops suggest replacing them once they reach about 4 to 5 mm. B.C. requires at least 3.5 mm.
- Check their age. The last four digits of the DOT code give the week and year made. Rubber hardens with age, even with plenty of tread.
- Note where they're stored and which set was on which corner, so you can rotate them next season.
Let your phone keep track. Lugnut tracks each tire set's DOT age, storage spot and tread depth at every corner, logs every swap, and (with Lugnut Pro) tells you the right week to book, from the morning forecast and your province's rules. It's free for one vehicle, and Pro is free for the first month. Coming soon to theApp Store
General information, not legal or insurance advice. Confirm dates with your province and your insurer.