F1 wet races: intermediates vs wets explained
F1 wet races use intermediate tyres for damp or drying tracks and full wets for heavy rain and standing water, with Safety Car starts or red flags if conditions worsen.
In Formula 1, intermediate tyres are for damp or drying conditions, while full wet tyres are for heavy rain and standing water. F1 wet races are shaped as much by visibility and track drainage as by grip, which is why race control can order a Safety Car start or suspend running altogether.
Intermediate vs wet tyres
Intermediate and full wet tyres are both treaded tyres, but they are built for different levels of water on the track. The intermediate is the crossover option: it is intended for a surface that is wet enough for slick tyres to struggle, but not so flooded that large areas of standing water remain. Teams use it when the circuit is damp, drying, or only partly wet.
The full wet tyre is the heavier-rain option. Its deeper tread and more aggressive water-clearing design are meant for conditions with significant standing water, where the priority is reducing aquaplaning and keeping the car controllable at lower speed. In practice, the full wet is not simply a slower intermediate; it is a tyre for a narrower and more severe weather window.
When each tyre is used
Tyre choice in wet weather depends on grip, water depth, track temperature and, crucially, visibility. Drivers usually move to intermediates once the track no longer carries enough surface water to justify full wets, even if it is still raining. By contrast, full wets come into play when spray is heavy and the circuit has enough standing water to make intermediates risky.
That decision is not made by tyre labels alone. A track can be wet enough for full wets in one sector and close to intermediate conditions in another, so teams and drivers constantly reassess the crossover point. As the surface dries, the intermediate is generally the preferred wet-weather race tyre because it overheats and wears less severely than a full wet on a track that is losing water.
Safety Car starts and red flags
A wet race can start behind the Safety Car when race control judges that a normal standing start would be unsafe. The usual reasons are poor visibility from spray, too much standing water, or both. Running initial laps behind the Safety Car helps the field assess grip, allows cars to disperse some water, and gives officials another chance to judge whether conditions are improving enough for green-flag racing.
If conditions are too severe even for that, the race director can suspend the session with a red flag. That applies in Grands Prix, qualifying and other sessions when the circuit is considered unsafe because of heavy rain, flooding or visibility that falls below an acceptable level. Once conditions improve, the session can resume under the procedure set out in the sporting regulations; if they do not, the stoppage can be prolonged or the session can be ended.