After all the talk of rain and even thunderstorms, it looks as though the Canadian Grand Prix, like the seven preceding rounds of the 2005 Formula One World Championship will take place in blistering heat. Although it is not sunny, more overcast, it is very, very warm.

The 'topsy-turvy' 2005 season continues to surprise, with Jenson Button starting from pole position today ahead of Michael Schumacher. Although the German says that he was always confident of a good qualifying positions - the opposite of what he was saying on Friday, Button admits to being shocked at starting from pole.

The big question today, is whether either of these men can convert their excellent starting positions into strong points, indeed podium, finishes, especially in light of their respective seasons thus far.

Button, indeed BAR, has yet to score a point this season - other than those scored at Imola and subsequently taken away in light of the fuel tank saga, while Schumacher's best finish is a second at Imola, the very race from which BAR were later excluded from.

Other factors will play a key role this afternoon however. The German will have noted the gearbox problem that resulted in his teammate having to start from the back of the grid, while both he and Button will be aware that the Renaults and McLarens are right behind them on the grid.

The other factors this afternoon, especially in light of Kimi Raikkonen's 'retirement' from the European Grand Prix, is tyre wear and brake wear, both tyre and brakes will be pushed to the very limit during today's race on a track that is the fourth fastest - in terms of percentage of the lap done flat-out - on the calendar. A track that is well known for it pile-ups and incidents.

Opinion over the issue of tyre wear is mixed, with some arguing that the new rules will end in disaster, while others say that drivers will now have to learn how to respect their tyres.

Then again, there is the Montreal circuit itself, which has been completely re-surfaced ahead of this year's race. The Trouble is, the new asphalt has been breaking up, and where the surface has been repaired, the track has been left slightly uneven and very dirty. This is particularly noticeable at the final chicane, scene of the so-called Champions Wall.

Finally, let's not forget the ever-present factor in contemporary F1, fuel strategy. Is Button running extra light, indeed is that the reason for, local hero, Jacques Villeneuve's superb qualifying position.

As the cars prepare to head off on the warm-up lap, the air temperature is 32 degrees, while the track temperature is 47 degrees. Humidity however, is a staggering 58%. All of this is going to add to the 'burden' on the brakes and tyres.

Rubens Barrichello has opted to start from the pitlane.

On the warm-up lap Button encounters a problem with gear selection, however he continues, having advised his team by radio. As a result of the problem, and acting on orders, he leads the field round very, very slowly.

The grid forms, it feels like an eternity.

A dreadful start by Schumacher, and indeed Button, with both Renaults nipping through to take the lead, while McLarens also get past the German. Somehow they get through the first corner without incident, though Michael loses a whole load of positions.