The boys were found in good spirits at 5.07am on Sunday on the island Stora Kvisslan in Lake Hjälmaren, west of Stockholm.
A helicopter discovered their boat and could then direct the emergency services searching for the missing boys, police confirmed.
“They were in relatively good spirits,” Thomas Ginghagen at Örebro police said.
The alarm was sounded at 9pm on Saturday evening when the boys had not returned home.
“The parents were themselves on their way out to rescue them, but it was so windy that were not able to get out,” Gunnar Corp at Örebro police told news agency TT.