The Swiss race is designed to prepare riders for the Tour de France starting with Tuesday's 4.8km prologue at Aigle, and including two mountain finishes before culminating with a tough 17.8km time-trial Sunday in Lausanne.
Faithful to his winning pre-Tour de France formula the 31-year-old Briton will be backed up by French teammate Kenny Elissonde, whose help will be particularly precious in the mountains.
Froome won the Swiss race in 2013 and 2014 going on to win the Tour de France in 2013, 2015 and 2016.
This year's race brings together the 18 World Tour teams plus one invitation for Belgian outfit Wanty.
Several big names are absent including last year's top two Nairo Quintana of Colombia and France's Thibaut Pinot, who will compete in the Giro d'Italia on May 5th.
Swiss rider Michael Albasini has already won six stages and will bid to close in on the overall record of 12 held by Italian Mario Cipollini.
Unluckily for the riders, the start of the Tour coincides with the beginning of a rainy, cold spell after many weeks of sunshine.
According to MeteoSuisse “significant precipitation” is predicted for all regions of the country. “It brings an end to a period of dry weather that has lasted more than four weeks in certain areas of French-speaking Switzerland”.
Until now, the sun has shone in the region for 40-50 hours more than normal during April, it added.
The last “significant” rainfall in the area was on March 22nd.
And if that wasn't bad enough for the Tour cyclists, a drop in temperatures means snowfall is predicted down to 800m on on Wednesday.
That day the Tour route takes riders from Aigle in the Rhône valley up to Champéry at 1,033m.
Riders also faced snow and chilly conditions in last year's race.