Bad weather is where The Highway Code stops giving short orders and starts giving judgement calls. Only a few of its weather rules are written as legal requirements. This article reads the Highway Code section on adverse weather (rules 226 to 237) and the general rules on speed and stopping distances, all read on 28 October 2026. The Code applies to England, Scotland and Wales, and nothing here covers Northern Ireland.
How to tell a legal rule from advice
The Code’s introduction explains its wording. Rules that use the words MUST or MUST NOT are legal requirements, and breaking them is a criminal offence for which a driver may be fined, given penalty points or disqualified. Failing to follow the other rules will not, in itself, cause a prosecution, but the Code says it may be used in evidence in court proceedings under the Traffic Acts to establish liability. That includes rules that use advisory wording such as “should” or “do not”.
The weather rules that carry a MUST
- Rule 226, headlights: a driver MUST use headlights when visibility is seriously reduced, generally when unable to see for more than 100 metres (328 feet). Front or rear fog lights may also be used, but MUST be switched off when visibility improves.
- Rule 229, clear windows and lights: before setting off in icy or snowy weather, a driver MUST be able to see, so all snow and ice must be cleared from all windows, and lights must be clean with number plates clearly visible and legible.
- Rule 236, fog lights: a driver MUST NOT use front or rear fog lights unless visibility is seriously reduced, because they dazzle other road users and can obscure brake lights.
Rain: space matters more than anything else
Rule 227 says that in wet weather stopping distances will be at least double those needed on dry roads, because tyres have less grip. It advises keeping well back from the vehicle in front. It also says that if the steering becomes unresponsive, water is probably preventing the tyres from gripping, and the answer is to ease off the accelerator and slow down gradually. It warns that rain and spray from other vehicles can make it hard to see and be seen, and that spilt diesel makes the surface very slippery.
The general rule on following distance, rule 126, asks for at least a two-second gap on high-speed roads and in tunnels where visibility is reduced, with the gap at least doubled on wet roads and up to ten times greater on icy roads. Rule 125 adds that the speed limit is the absolute maximum, not a safe speed whatever the conditions, and that drivers should reduce speed when weather conditions make it safer to do so.
Ice and snow: first decide whether to go
Rule 228 tells drivers in winter to check the local forecast for warnings of icy or snowy weather, and not to drive in those conditions unless the journey is essential. If it is, it says to take great care, allow more time, and carry an emergency kit that it lists as including de-icer, an ice scraper, a torch, warm clothing, jump leads, a shovel, a warm drink and emergency food.
Rule 229 turns that into a pre-journey routine. Beyond the legal duty to clear the windows, lights and number plates, it advises making sure the mirrors are clear and the windows are demisted thoroughly, removing any snow that might fall off into the path of other road users, and checking that the planned route is clear of delays and that no further snow or severe weather is forecast. A small cleared patch on the windscreen is not enough. For a learner, a lesson or practice drive can usually be rearranged, so a booking on the calendar is not a reason to set off in conditions you have not driven in before.
Once on the road, rule 230 says stopping distances can be ten times greater than on dry roads. Rule 231 asks for slow driving in as high a gear as possible, with gentle acceleration and braking, particular slowness on bends, and a gentle test of grip in a safe place. It notes that on ice, tyres make virtually no noise. Rule 119 covers skids: release the brake pedal fully or ease off the accelerator, then steer in the direction of the skid.
Fog: seeing is not stopping
Rule 234 says to check mirrors and slow down before entering fog, and to expect a bank of fog or drifting patches where a sign warns of fog even if the road ahead is clear. Under rule 235, a driver should be able to pull up well within the distance that can be seen clearly. The rule warns that rear lights can give a false sense of security, and advises not accelerating away from a vehicle that is too close behind.
Wind and heat
Rule 232 says high-sided vehicles are most affected by windy weather, but strong gusts can also blow a car, cyclist, motorcyclist or horse rider off course, notably on open stretches exposed to crosswinds, at bridges or at gaps in hedges. Rule 233 says that in very windy weather a vehicle may be affected by turbulence created by large vehicles, and that motorcyclists are particularly affected, so drivers should keep well back from a motorcyclist who is overtaking a high-sided vehicle. In practice, that means looking ahead for the exposed places rule 232 names, such as a bridge or a gap in a hedge, and not choosing that spot to pass a cyclist or horse rider, who may be pushed off course by a gust. In hot weather, rule 237 advises keeping the vehicle well ventilated to avoid drowsiness, notes that the road surface may soften or turn slippery if it rains after a dry spell, and says to slow down and, if necessary, stop if dazzled by bright sunlight.
What the weather rules leave open
None of the weather rules read for this article gives a speed in miles per hour. They use measures such as 100 metres of visibility or a doubled gap, and leave the rest to the driver’s judgement.
The bottom line
In the Highway Code’s adverse weather section, the legal requirements concern headlights in seriously reduced visibility (rule 226), clear windows, lights and number plates in snow and ice (rule 229), and fog lights (rule 236). Everything else is written as advice, and the Code says that advice may still be used in evidence if a collision case reaches court.
Sources
- The Highway Code: Driving in adverse weather conditions (226 to 237), GOV.UK, read 28 October 2026 (gov.uk)
- The Highway Code: General rules, techniques and advice for all drivers and riders (103 to 158), GOV.UK, read 28 October 2026 (gov.uk)
- The Highway Code: Introduction, GOV.UK, read 28 October 2026 (gov.uk)
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