[3] Former multiple Tour of California stage winner Jens Voigt was a race ambassador, served as a television analyst and was an adviser to the organizers.

Outsiders included Jacques Janse van Rensburg (MTN–Qhubeka), Janez Brajkovič (UnitedHealthcare) – a former Tour de France top-10 finisher – as well as Matthew Busche (Trek Factory Racing), Rob Britton (Team SmartStop) and Phil Gaimon (Optum–Kelly Benefit Strategies).

[10] Other contenders for stage honors included Lucas Sebastián Haedo of Jamis–Hagens Berman, Danny van Poppel (Trek Factory Racing) and Guillaume Boivin (Optum–Kelly Benefit Strategies).

[13] A breakaway of four riders formed early on, consisting of Will Clarke of Drapac Professional Cycling, Steve Fisher of Jelly Belly–Maxxis, recent Tour of the Gila winner Rob Britton of Team SmartStop and his teammate Robert Sweeting; this quartet's gap grew to a maximum of around six-and-a-half minutes.

With about 60 miles (96.6 kilometers) to cover, one of the favorites, Andrew Talansky (Cannondale–Garmin) abandoned the race due to a combination of allergies and an upper respiratory infection.

[14] At the front, the four riders in the break were forming a mini-echelon to shelter themselves from the winds, when Britton suffered a mechanical and decided to sit up and wait for the peloton.

Etixx–Quick-Step took to the front of the field with 2 miles (3.2 kilometers) to cover, with Renshaw leading out Mark Cavendish for his tenth victory of the season, ahead of Peter Sagan and Jempy Drucker; no overall classification contenders lost time on the fast run-in.

The breakaway enjoyed a maximum advantage of just over five minutes in the flat, open terrain,[20] with Etixx–Quick-Step controlling the pace for race leader Mark Cavendish.

[24] One of the category 4 climbs was situated at the end of the stage in San Jose, where the finale featured 250 meters (820 feet) at an average gradient of 10%.

[33] As the riders reached the last intermediate sprint in Arroyo Grande – again won by Daniel – with 20 miles (32.2 kilometers) to go, the break held a 35-second lead.

Daniel Oss (BMC Racing Team) tried his luck under the red kite, but was joined with about 100 meters (330 feet) remaining as Sagan powered his way past him to claim his second victory of the season, followed by Wouter Wippert (Drapac Professional Cycling) and Mark Cavendish.

The very steep climb of Balcom Canyon was won by Morton, while behind Chris Butler of Team SmartStop attacked from the main field and tried to bridge to the escapees.

[40] With the rain making the roads slippery, the lead group split in two with only Howes, Curran and Wyss remaining clear with a gap of 1' 50" with 25 miles (40.2 kilometers) to race.

Hincapie Racing Team and Etixx–Quick-Step marshaled the peloton, but they were unable to make ground in the rain, with the leaders continuing to lead by 1' 50" with 14 miles (22.5 kilometers) to the finish.

Danny Pate of Team Sky and some Drapac Professional Cycling riders came to the fore to help out with the chase, but Wyss attacked the break after a crash occurred in the field.

[41] A bunch sprint ensued on drier roads in Santa Clarita, with Mark Cavendish taking his third stage victory,[39] beating Zico Waeytens (Team Giant–Alpecin) by a bike length.

[41] Big Bear Lake, situated at an altitude of 6,000 feet (1,828.8 meters), was supposed to welcome the event but was forecast to receive 2–5 inches (51–127 millimeters) of snow.

[43] As a result, race organizers opted to move the event 100 miles (160 kilometers) east to Santa Clarita, with the Six Flags Magic Mountain theme park serving as both the start and finish location of the stage.

Therefore, Carson Miller of Jamis–Hagens Berman, who, in 133rd place trailed overall leader Toms Skujiņš (Hincapie Racing Team) by forty-two minutes and eighteen seconds, was the first rider to set off on the final stage.

Mark Cavendish – standing 62nd in the general classification – overtook the rider in front of him, sprinter Zico Waeytens (Team Giant–Alpecin), as he finished thirty seconds down on van Emden's time.

[48][46] The queen stage of the 2015 Tour of California, the riders contended with the first King of the Mountains climb, the second-category ascent of Glendora Ridge Road.

The other breakaway riders were Gregory Brenes (Jamis–Hagens Berman), Lasse Norman Hansen (Cannondale–Garmin), Chris Butler (Team SmartStop), Daniele Ratto (UnitedHealthcare) and Johann van Zyl of MTN–Qhubeka.

[51] Before the end of the climb, Skujiņš – who was second in the general classification – returned to the peloton; Lachlan Morton of Jelly Belly–Maxxis joined the break as Ratto and Norman Hansen were distanced.

Norman Hansen led the breakaway group through the intermediate sprint, prior to a mostly uphill section for 25 miles (40.2 kilometers) until the finish line.

After Oss won maximum points at the Glendora Mountain Road climb, he dropped back to the peloton, leaving van Zyl on his own out front.

2012 Mount Baldy stage winner Robert Gesink of LottoNL–Jumbo was dropped with 3.5 miles (5.6 kilometers) to cover, while young rider classification leader Julian Alaphilippe (Etixx–Quick-Step) took the lead of the very depleted group.

He soloed through the twisting final kilometres featuring bad tarmac, and held on to take his first win of the season after numerous podium placings.

[57] This stage was supposed to have no consequences on the general classification due to its flat terrain, but the two-second difference separating Julian Alaphilippe and Peter Sagan meant that the Tour was not yet decided.

A breakaway was formed, consisting of two Etixx–Quick-Step riders, Matteo Trentin and Yves Lampaert, Danny Pate (Team Sky), Jacques Janse van Rensburg (MTN–Qhubeka) and Ruben Zepuntke (Cannondale–Garmin).

The leader of the young rider classification received a white and red jersey, sponsored by bicycle component manufacturer SRAM Corporation.