Mercedes driver Lewis Hamilton has claimed his fifth Canadian Grand Prix pole position using the P Zero Purple ultrasoft, in the coolest qualifying session held all year. Despite temperatures at the start of the session of just 17 degrees centigrade ambient and 20 degrees on track, Hamilton's pole time of 1m12.812s was only around half a second slower than the all-time lap record (1m12.275s) set by Ralf Schumacher in 2004.

The ultrasoft was used from the very start of qualifying by all the teams with the exception of Force India, which also ran the supersoft. By the end of qualifying, all the top 10 drivers had used four sets of ultrasoft, apart from the Red Bulls, which used five.

Drivers had to balance the constant track evolution (with more rubber being laid on track) versus the risk of weather deteriorating when it came to the timing of their final qualifying laps. In these cool conditions, tyre warm-up was crucial, with comparatively long runs possible even on the ultrasoft. However, Montreal is traditionally the circuit where pole counts for least: only six from the last 14 races here have resulted in a win from pole.

Paul Hembery: "With uncertain weather conditions both today and tomorrow, there were a number of question marks during qualifying that will be carried through to the race. Track temperature is clearly a key aspect to tyre behaviour here, but we won't know exactly how that develops until just before the race: cool temperatures seem to be indicated, and there might even be some rain. With low wear and degradation, a one-stopper seems the most likely scenario. However, teams will have to keep an open mind on strategy and react to changing conditions as they happen: a traditional hallmark of this fantastic track. We've seen in the past that pole position is not necessarily the key to success here, so everything is still wide open."

How the tyres behaved today

Soft: used in free practice but not qualifying. A mandatory set for the race (if it's dry).

Supersoft: quite close to the ultrasoft here both in terms of wear and degradation.

Ultrasoft: the fastest tyre by 0.6s per lap, making it the default choice from Q2 onwards.

Race strategy

Track temperature will determine what the optimal strategy is for the 70-lap race tomorrow. If it's cold, we're looking at a one-stopper: starting on supersoft and then moving to soft on lap 26 is theoretically the fastest way.

If starting on ultrasoft (which all the top 10 will do), the strategy is extremely similar, with the change to soft coming one lap earlier, on lap 25.

Check out our Saturday gallery, here.