Fog Lights: When to Use Them and When to Switch Them Off

Use fog lights only when visibility is seriously reduced, generally when you can’t see more than 100 metres ahead, and switch them off as soon as it clears. That’s the Highway Code rule. Leaving them on in clear weather dazzles other drivers and can hide your brake lights.

Autumn and winter bring thick morning fog to Greater Manchester, often around the M60 and on open roads. This guide explains when fog lights are allowed, how to find them, and how to drive safely when you can hardly see.

• Rule 226: you MUST use headlights when visibility is seriously reduced, generally when you can’t see for more than 100 metres. You may also use front or rear fog lights.
• Rule 236: you MUST NOT use fog lights unless visibility is seriously reduced, because they dazzle other road users and can hide your brake lights. You MUST switch them off when visibility improves.

A simple check: 100 metres is roughly the length of a football pitch, or about 25 car lengths. If you can’t see that far, fog lights are allowed. If you can, they should be off.

• Rear fog light: a very bright red light that helps drivers behind see you. Every modern car has at least one. The dashboard symbol is usually amber, a lamp shape facing right with wavy lines through the beams.
• Front fog lights: low-mounted white lights fitted to some cars. The symbol is usually green, a lamp shape facing left with wavy lines.

Fog lights usually only work with dipped headlights on. The switch is often on the light stalk or a dial by the steering wheel. Check your car’s handbook, and ask your instructor to show you during a lesson. Knowing where the switches are is also useful for the show me tell me questions.

1. Check your mirrors, then slow down before you enter fog.
2. Use dipped headlights, not full beam. Main beam reflects off the fog and makes it harder to see.
3. Leave a bigger gap. Following the rear lights of the car in front can give a false sense of security.
4. Be able to stop well within the distance you can see clearly, especially on motorways and dual carriageways.
5. Use your wipers and demisters to keep the windscreen clear.
6. At junctions with poor visibility, stop in the correct position, wind the window down and listen for traffic before you pull out.
7. Don’t speed up to get away from a car that is too close behind you.

• Forgetting to switch the rear fog light off when the fog lifts. Drivers behind may mistake it for brake lights.
• Using fog lights in rain or at night when you can still see well. That’s not what they’re for.
• Relying on daytime running lights. On many cars they don’t light up the back of the car, so drivers behind can’t see you.

Our DVSA-approved instructors teach you to drive confidently in fog, rain and the dark, not just on sunny days. Manual and automatic lessons across Greater Manchester, from £35 an hour, 7 days a week from 7am to 11:30pm.

• Winter driving lessons in Manchester
• Night driving tips for beginners
• Dashboard warning lights explained

Fill in the form and we’ll match you with an instructor near you, or call 07758 837589.

The Highway Code: driving in adverse weather conditions (rules 226 to 237), GOV.UK. Checked 12 November 2026.

When should you use fog lights in the UK?

Only when visibility is seriously reduced, generally when you cannot see more than 100 metres ahead. Switch them off as soon as visibility improves.

Is it illegal to drive with fog lights on?

The Highway Code says you must not use fog lights unless visibility is seriously reduced, because they dazzle other road users and can hide your brake lights.

Should I use full beam in fog?

No. Use dipped headlights. Full beam reflects off the fog and makes it harder to see.

What does the fog light symbol look like?

The rear fog light symbol is usually amber, a lamp facing right with wavy lines through the beams. Front fog lights usually show a green symbol facing left. Check your handbook, as cars vary.

Do learner drivers need to know about fog lights?

Yes. You need to know when to use them for the theory test and for driving safely, and how to switch on the lights can come up in the show me tell me questions.