In short. No law requires winter tyres in Britain, and none bans them in summer. The Department for Transport said in January 2024 that it had no plans to require them, and in February 2026 that the rarity of heavy snow and the known drawbacks of winter tyres in warm weather did not support a detailed assessment. The Highway Code and the MOT manual do not mention them, and the usual tread rule applies to them: 1.6 mm across the central three-quarters. They pay off if you often drive on cold, wet or snowy roads, and they matter once you drive abroad: Germany asks for a winter tyre with the Alpine symbol (3PMSF) on every wheel in winter conditions, France and Austria have winter periods, and M+S alone has not been enough in Germany since 1 October 2024 or in France since 1 November 2024. On timing, the famous 7 °C is a maker's rule of thumb that no published test pins down. In Met Office records for 1991 to 2020, the average night minimum falls below 7 °C from mid-September in the Scottish Borders uplands to early November in London, and the average temperature from late October to early December. The practical rule is to fit before the first frost on your usual journeys, and to take them off once nights stay above 7 °C, from late April in the south to early June in the uplands, rather than leaving them on through the summer.
What the law says at home
| Question | Answer | Source |
|---|---|---|
| Are winter tyres compulsory? | No. The Government has no plans to make them so | Department for Transport, written answers of 15 January 2024 and 3 February 2026 |
| Is it illegal to drive on winter tyres in summer? | No law bans it | A tyre maker's UK page |
| What does the Highway Code say? | In icy or snowy weather, do not drive unless the journey is essential; it does not mention winter tyres | Highway Code, rules 228 to 231 |
| Minimum tread | 1.6 mm across the central three-quarters of the tread and round the whole circumference, for a car | MOT inspection manual; Highway Code, annex 6 |
| Can I mix tyres on an axle? | Tyres of different structure, such as radial and cross-ply, must not share an axle (major defect), nor tyres of different size (major defect) | MOT inspection manual, 5.2.3 (b) and (c) |
| Does the MOT look at snow performance? | The manual does not mention it; it checks condition, tread depth, fitment and the pressure monitoring system | MOT inspection manual, 5.2.3 |
The sources are the two written answers (second one), the Highway Code's winter weather rules, its annex 6 and the MOT inspection manual. A tyre maker's UK page says there is no UK law banning winter tyres in summer, adds that there is no specific insurance rule against it, and suggests asking your insurer if you are unsure (Michelin UK, winter tyres in summer). The manual lists no defect for a tyre's season; it looks at whether the tyre is safe, legal and correctly fitted. Our guide to MOT, TPMS and aftermarket wheels covers the pressure monitoring system.
M+S, the snowflake and all-season: what the markings mean
Three words are used loosely, so here is what the regulation says. UN Regulation 117 defines a snow tyre as one whose tread pattern, compound or structure is mainly designed to do better in snow than a normal tyre at starting, keeping motion and stopping. It provides for the inscription M+S on a tyre designed to do better than a normal tyre in mud and fresh or melting snow, and for the Alpine symbol (a three-peaked mountain with a snowflake) on a tyre that is classified in the snow category. To be classified, a car tyre must reach a snow index of at least 1.07 by the braking method or 1.10 by the traction method, against a reference tyre, on compacted snow between -2 °C and -15 °C (UN Regulation 117, OJ L 307, 2011). A snow index of 1.07 means 7 per cent better than the reference tyre in that test.
| Marking | What it says | Test behind it | Where it settles the question |
|---|---|---|---|
| M+S (also M.S or M&S) | The maker says the tyre does better than a normal tyre in mud and snow | We found no snow-grip test attached to it in the regulation; a tyre maker describes it as the maker's own declaration | Named by the Austrian ministry. Not enough alone in Germany (since 1 October 2024) or France (since 1 November 2024) |
| Alpine symbol (3PMSF) | The tyre is in the snow category | Yes: the snow index of Annex 7 | The mark the German definition asks for; in France it must come with M+S |
| All-season | No regulatory definition | Only if it bears the Alpine symbol | Counts as a winter tyre in Germany and France only if it carries the Alpine symbol |
For France, the decree defines a winter tyre as one with the Alpine symbol together with M+S, and the road safety authority says an all-season tyre has no regulatory definition and counts as a winter tyre only with the 3PMSF mark (Légifrance, decree no. 2020-1264; Sécurité routière, in French). For Germany, the traffic regulations require the Alpine symbol (StVZO, section 36, in German). A tyre sold in Britain with M+S and no snowflake can therefore be fine at home and not meet the definition abroad. Check the sidewall for the snowflake before a trip to either country. Our guide to snow chains and snow socks sets out the rules country by country.
Winter tyres on a British car in Europe
| Country | Marking and period | Tread named | Source |
|---|---|---|---|
| Germany | Winter conditions only (black ice, slippery snow, slush, ice, frost glaze); the Alpine symbol is required on every wheel | The general 1.6 mm; a motoring magazine recommends 4 mm | StVO section 2; StVZO section 36 |
| France | 1 November to 31 March in listed mountain communes; Alpine symbol with M+S, or chains on board | Not set in the decree | Decree no. 2020-1264 |
| Austria | 1 November to 15 April, in wintry conditions; the ministry names the M+S marking | At least 4 mm (radial) or 5 mm (cross-ply) | KFG section 102; KDV section 8; ministry page |
In Austria the ministry adds that an accident on summer tyres in winter conditions leaves the driver partly at fault unless the driver can show it would have happened anyway (BMIMI). The winter tyre must also match the car: the Austrian regulation asks for a speed capability at least equal to the car's design speed, and at least 160 km/h where that is higher, with a label in the driver's view if the tyre is slower than the car (KDV, section 8, in German). German rules allow a lower speed index on a winter tyre if the limit is shown in the driver's view and respected (StVZO, section 36). We found no British rule on that point; the MOT manual's speed-rating and load-rating checks are for the heavier classes 5 and 7, not cars. The car maker's handbook is the place to check the speed index for your car.
The 7 °C rule: where it comes from and what it is worth
| Source | What it says |
|---|---|
| Michelin UK | When the road temperature falls below 7 °C, switch to winter tyres; leaving them on all year is legal but Michelin recommends changing them when temperatures stay above 7 °C; changing at Halloween and again at Easter is offered as another guide |
| Continental UK | When the seasonal temperature falls below 7 °C (46 °F), switch to winter tyres; above it, fit summer tyres |
| AUTO BILD (14 October 2026) | Makers have claimed this since the 1980s at the latest; the magazine says that in some of its own tests summer tyres braked better than winter tyres on dry roads, even at slightly sub-zero temperatures; no precise limit has been found in published tests, and there is no fixed temperature |
| ADAC (via t-online) | The old rule is out of date; it was meant to prompt drivers to fit winter tyres before ice and snow |
| TNPF (French tyre makers' association) | Cracking of the tread of a summer tyre is an issue at very low temperatures, of the order of -20 °C, not at 7 °C |
The makers' pages are Michelin UK on when to fit, its page on European rules and Continental UK; the doubts come from AUTO BILD (in German; our translation), from the ADAC's experts as reported by t-online (in German) and from the TNPF (in French). The magazine adds a point that favours winter tyres: in winter the roads are mostly damp, including in the morning with dew, and today's winter tyres can be safer there than today's summer tyres. So the 7 °C figure is a planning aid, not a physical threshold, and not a law.
When does the UK get below 7 °C?
The Met Office publishes monthly station records. We took the monthly average maximum and minimum for 1991 to 2020 at twelve stations (which have a full 30 years), took the mean of the two as the average temperature, and placed each monthly value at mid-month. A date is where the line between two mid-months crosses 7 °C, rounded to the start, middle or end of a month. These are estimates for an average year; a given autumn can differ by weeks.
| Station (height) | Mean daily minimum below 7 °C from | Back above 7 °C from | Mean temperature below 7 °C from | Back above 7 °C from |
|---|---|---|---|---|
| Aberporth, west Wales (133 m) | early November | early May | early December | mid-March |
| Yeovilton, Somerset (20 m) | late October | mid-May | late November | mid-March |
| Heathrow, London (25 m) | early November | late April | early December | early March |
| Cardiff Bute Park (9 m) | late October | late April | early December | early March |
| Cambridge NIAB (26 m) | late October | mid-May | late November | mid-March |
| Sheffield (131 m) | late October | early May | mid-November | mid-March |
| Armagh, Northern Ireland (62 m) | mid-October | mid-May | mid-November | mid-March |
| Durham (102 m) | early October | late May | mid-November | late March |
| Newton Rigg, Cumbria (169 m) | late September | late May | early November | early April |
| Leuchars, Fife (10 m) | early October | late May | early November | early April |
| Stornoway, Western Isles (15 m) | mid-October | late May | mid-November | early April |
| Eskdalemuir, Scottish Borders (242 m) | mid-September | early June | late October | mid-April |
What the table says:
- The answer depends on what you measure. On the night minimum, the 7 °C line is crossed from mid-September at Eskdalemuir to early November at Aberporth and Heathrow. On the average temperature, it is crossed from late October to early December.
- The south and east are close to Halloween on the minimum. Yeovilton, Cardiff, Cambridge and Sheffield cross in late October, London and west Wales in early November. The north and the uplands cross earlier, between mid-September and mid-October.
- In spring, Easter is early for the minimum. Easter Sunday 2027 is 28 March. By then the average temperature is back above 7 °C at seven of the twelve stations (early to mid-March), but the average night minimum stays below 7 °C until late April at the earliest (London and Cardiff) and early June at the latest (Eskdalemuir).
- Frost comes after the 7 °C line. When the average night minimum passes 7 °C, few air frosts have happened yet: in October the average is below 3 days at eleven of the twelve stations (4.3 days at Eskdalemuir), and in November it runs from 0.6 days at Aberporth to 9.3 at Eskdalemuir. The average number of days of air frost is below.
| Station | October | November | March | April |
|---|---|---|---|---|
| Aberporth | 0.0 | 0.6 | 1.8 | 0.4 |
| Yeovilton | 1.8 | 5.5 | 7.6 | 3.8 |
| Heathrow | 0.3 | 2.7 | 3.0 | 0.8 |
| Cardiff Bute Park | 1.0 | 3.7 | 3.9 | 1.4 |
| Cambridge NIAB | 0.7 | 3.7 | 5.2 | 2.6 |
| Sheffield | 0.4 | 2.4 | 3.6 | 1.1 |
| Armagh | 0.8 | 3.5 | 5.3 | 2.3 |
| Durham | 1.2 | 4.6 | 6.5 | 3.2 |
| Newton Rigg | 2.9 | 7.1 | 8.6 | 4.8 |
| Leuchars | 1.6 | 6.8 | 8.2 | 3.4 |
| Stornoway | 0.2 | 1.4 | 3.9 | 1.4 |
| Eskdalemuir | 4.3 | 9.3 | 11.9 | 7.5 |
The source is the Met Office's station data files, one per station, listed in the sources below. The files mark some months as estimated, from none at Heathrow to 33 of the 360 months at Cardiff Bute Park. The Met Office's own published averages may differ slightly from ours, which use the mean of the maximum and minimum rather than a 24-hour mean.
Fitting: how to decide
- Fit before the first frost on your usual journeys, not on the first snowfall. AUTO BILD gives the same test: before frost, black ice, slush or snow are to be expected on the roads you drive. The table above tells you roughly when nights drop below 7 °C where you live.
- Book early, or have the wheels ready if you change them yourself. AUTO BILD says that anyone who does not change their own wheels should look for a workshop appointment by early October at the latest, because diaries fill quickly once temperatures fall.
- Fit four, not two. A tyre maker's UK page warns that winter tyres on only the front two or only the rear two can be dangerous, and recommends the same tyres on all four wheels (Michelin UK, how many winter tyres). France's decree asks for winter tyres on at least two wheels of each axle, which on a car means four; Austria's ministry says winter tyres on all four wheels.
- If you are going abroad, go by the stricter country and the earlier date. The Austrian and French periods both start on 1 November, a Sunday in 2026.
- Check the sidewall for the snowflake if you will drive in Germany or France, and the tread depth: Austria sets 4 mm for a radial winter tyre in the period, against the British legal 1.6 mm.
Removing them: how to decide
- Nothing in British law asks you to remove them. They are legal all year.
- The reason to remove them is in the braking test. The ADAC compared three winter tyres with different remaining tread to a summer tyre on dry roads at 10 to 13 °C and at 35 °C. From 100 km/h (about 62 mph) the winter tyres stopped later, by up to 16 m (about 52 ft) in the worst case; with 4 mm left the gap fell to 5 m (about 16 ft). The club says the gap grows with tread depth and temperature. In its worked example, a car on summer tyres stops before an obstacle while the same car on winter tyres still has speed of around 37 km/h (about 23 mph) (ADAC, in German; our translation).
- The club's advice for spring. April and May are less critical because temperatures are not yet constantly high; it calls the summer a safety risk for winter tyres, and says nearly new winter tyres should be kept for next winter rather than used up in summer.
- The makers' dates. A tyre maker's UK page says you can generally wait until late March or the change to summer time (28 March 2027 in Britain); it also notes that winter tyres have higher rolling resistance.
- Whichever figure you read, it is a range. Read on the night minimum, the 7 °C line is back above only from late April (London, Cardiff) to early June (Eskdalemuir); read on the average temperature, from early March to mid-April. A forecast for your own roads is a better guide than either.
Winter tyres and your wheels
A second set of complete wheels means the tyres stay on their rims and the changeover is a swap of wheels, and it lets you store the off-season set ready to fit; our guide to alloy and steel wheels for winter covers the choice of wheel. Each set needs its own pressure sensors if your car has them, as the tyre pressure guide and the MOT and TPMS article explain. At the change, torque the nuts to the car maker's figure and re-check them after a short drive (wheel nut torque), and have each tyre balanced (wheel balancing). Note each wheel's position before you put the set away, and read how to store tyres and wheels between seasons and tyre rotation for the rest.
Wheels from Onyx Forged
We do not give a tyre size for winter, and we do not publish a pressure for your car: the figure is your car maker's and your tyre's. Onyx Forged is a French brand of made-to-order forged wheels, designed to JWL/VIA standards. The Onyx Forged design office works out the wheel for the car as you described it and checks it with you before anything goes into production; a second set for the winter is ordered the same way, and you can customise one. If you are unsure about a tyre size for made-to-order wheels, ask customer service before the tyres are fitted, not after. The winter tyres, their fitting, the sensors and the balancing are done by your tyre fitter. Say at the start that the set is for winter and that the car may see road salt: the terms and conditions list corrosion linked to de-icing salt among the warranty exclusions, with a shorter finish warranty in that case (article 6.2). See Onyx Forged and the catalogue.
Frequently asked questions
Are winter tyres compulsory in the UK?
No. The Department for Transport has said it has no plans to make them so, and the Highway Code and the MOT manual do not mention them.
Is it illegal to leave winter tyres on in summer?
No law bans it, according to a tyre maker's UK page. The ADAC advises against it because dry-road braking gets longer in warm weather, by up to 16 m from 100 km/h in its worst case.
When should I fit winter tyres in the UK?
Before the first frost on your usual journeys. In Met Office records for 1991 to 2020, the average night minimum drops below 7 °C between mid-September (Scottish Borders uplands) and early November (London and west Wales), so for most of England and Wales late October to early November is the usual time; the north and uplands are earlier.
When should I take them off?
Once nights stay above 7 °C. On the same records the average minimum is back above 7 °C from late April at the milder stations to early June in the uplands. A tyre maker's UK page says you can generally wait until late March or the change to summer time.
Is the 7 °C rule true?
It is a planning aid from the tyre makers. AUTO BILD, which traces it to the 1980s, says published tests have not found a precise limit; the ADAC's experts call it out of date; the French makers' association puts the cracking risk of a summer tyre at around -20 °C.
Do I need the snowflake symbol?
In the UK no marking is required. In Germany and France the Alpine symbol is needed, and M+S alone does not meet the definition. Austria's ministry names the M+S marking.
Should I fit two winter tyres or four?
Four. A tyre maker's UK page warns that two on one axle only can be dangerous; France's decree asks for two per axle, which means four on a car, and Austria's ministry asks for all four wheels.
How much tread should a winter tyre have?
The British legal minimum is 1.6 mm across the central three-quarters. Austria asks for 4 mm on a radial winter tyre during its winter period. The ADAC suggests 4 to 5 mm at most for winter tyres used into spring, and not less than 3 mm.
Do I have to tell my insurer?
The tyre maker's UK page says there is no specific UK insurance rule against winter tyres, and suggests asking your insurer if you are unsure. Policies differ and we have not read any, so ask.
Where to go next
For chains, socks and the rules abroad, read snow chains and snow socks: rules, sizing and clearance; for what to do with the set you take off, how to store tyres and wheels between seasons; for the positions at the next change, tyre rotation. Onyx Forged is a French brand of made-to-order forged wheels, designed to JWL/VIA standards: see Onyx Forged and the catalogue.
Sources
- UK Parliament, Department for Transport written answers: UIN 9007, 15 January 2024 and UIN 108977, 3 February 2026.
- GOV.UK: The Highway Code, driving in adverse weather conditions (226 to 237), annex 6 and the MOT inspection manual, section 5.
- UN Regulation No. 117, Official Journal of the European Union L 307, 23 November 2011: definitions, markings 4.2.6 and 4.2.7, snow index 6.4.
- Europe: Légifrance, decree no. 2020-1264 and Sécurité routière (in French); StVZO section 36 (in German); KDV section 8 (in German); BMIMI, winter tyres and snow chains.
- Met Office, station data (monthly maximum and minimum temperature and days of air frost; we averaged 1991 to 2020): Aberporth, Yeovilton, Heathrow, Cardiff Bute Park, Cambridge NIAB, Sheffield, Armagh, Durham, Newton Rigg, Leuchars, Stornoway and Eskdalemuir.
- Makers: Michelin UK, when to put on winter tyres, Michelin UK, European rules, Michelin UK, winter tyres in summer, Michelin UK, how many winter tyres and Continental UK, summer or winter tyres.
- Clubs and press: AUTO BILD, 14 October 2026, ADAC, winter tyres in summer and t-online, 26 February 2026, all in German (our translation); TNPF, summer tyres at low temperature (in French).
All pages were read on 15 October 2026.
The Onyx Forged design office.