Competitors were caught in the bad weather a few kilometers from the race finish at the top of the Col de Porte in the south-west of France.
“Many riders — including our boys — were hit by one hell of a hailstorm,” said a tweet from Israel Start-Up Nation (ISN).
“The scene was total chaos and mayhem … riders running for cover, hit hard by icy mini ping pong balls.”
Belgian cyclist Tim Declercq was left with large red welts on his back from the hail, which descended shortly after the race leaders had finished.
“As if Le Dauphiné was not painfull (sic) enough for the legs #hailstones,” Declercq wrote on Instagram.
He later posted a photo showing how the redness had started to subside.
Another rider, B&B Hotels-Vital Concept’s Maxime Chevalier, also had red marks across his back.
“It was crazy, the hail was so big,” said ISN’s Guy Niv in a video posted by the team on social media.
“Normally when you have this kind of hailstone you just stay home but we were still riding, we still had almost 2km to the top of the climb.
“I felt quite bad for the spectators as well on the side of the road because they were there without any shelter.
“It was quite painful actually. I just wanted to finish with it and go straight into the bus … it was not the best experience for the end of this day.”
According to ISN, one of the team’s riders took cover in a tent 500 meters from the finish, while Team Jumbo-Visma’s Tony Martin was given an inflatable raft to shelter under by a fan.
The 135km stage, which started in Vienne, was won by Slovenian rider Primož Roglic, who broke away from the lead pack in the final kilometer and finished eight seconds ahead of France’s Thibaut Pinot.