Tour de France Weather

Weather has always played a role in the Tour de France, and this year is no exception.  This year's tour has featured a large number of crashes, of which there are probably multiple causes, including weather.

Stage 10 pileup.  Photo: Graham Watson/VeloNews

For crashes, rain can be an issue, especially a light rain, which isn't sufficient to wash all the oil off the asphalt.  Further, the traffic lines in France are often made of plastic rather than paint, and can be quite slick when wet.  This contributed to a crash by Levi Leipheimer during stage 6.  Rain even influences the choice and tuning of equipment used by the riders.

Weather also affects strategy during the race.  Wind, for example, plays an important role in peloton dynamics.  Cross winds make drafting more difficult and can blow the peloton apart.  Special strategies are needed for dealing with strong cross winds, and astute riders can take advantage of the chaos they impose, including Lance Armstrong during the 2009 tour.   Riders can also take advantage of the wind to either launch or reel in attacks, depending on the circumstances.

Tour de France riders are at the limit of human endurance, and temperature and sun exposure play an important role.  The stages yesterday (12) and today (13) were the first mountain stages in the Pyrenees, but temperatures were cool.  Versus announcers suggested that temperatures at the Col du Tourmalet yesterday were about 45F.  Heat tolerance was not an issue for the riders, and the bigger concern was probably staying warm on the descent.  Riders donned windbreakers or stuffed newspapers in their jerseys for the descent.

Profile of Stage 12 of the 2011 Tour de France, including the
Col du Tourmalet.  Source: letour.fr

On a hot day, however, heat has caused some riders to "crack" during mountain stages, as happened to Bradley Wiggins during the 2010 tour.

Although I've been involved in weather support for the Winter Olympics, I've never had the opportunity to observe the efforts for the Tour de France.  I suspect it is a major undertaking.  The official Tour de France website contains weather forecasts for each of the stages about a day in advance.  The forecast for stage 14 suggest that pass temperatures will be cool tomorrow and that there will winds of as high as 45 km/h, certainly strong enough that they could play a role.

Source: letour.fr

Such forecasts provide some basic guidance for spectators, but the teams are certainly receiving more information than this, including weather observations from along the course during stages.