Orange flames lit up the night sky from Saturday into Sunday on hillsides just above the lights of inhabited areas, while thick black smoke billowed high into the air.
Late on Saturday, emergency services said the fire was now affecting 10 towns, although 11 had been evacuated as a precaution. No major tourist areas have been affected.
It covered an area of over 8,000 hectares (20,000 acres) with a perimeter of 70 km (40 miles), spreading from 5,000 hectares and a perimeter of 50 km early on Saturday.
Regional authorities said over 12,000 people had been evacuated, revising down their earlier provisional estimate of 26,000.
Weather conditions overnight were “better than expected” Tenerife’s fire brigade said on Sunday on X, formerly known as Twitter.
Fernando Clavijo, Canary Islands’ regional leader, said the largest firefighting deployment in the history of Tenerife had so-far prevented the loss of any homes.
Evacuations were ordered throughout Saturday due to worsening weather conditions. At a news conference late on Saturday, the head of Tenerife’s local government Rosa Davila described the fire as “devastating” and said it had forced new evacuations.
The blaze broke out on Wednesday in a mountainous national park around the Mount Teide volcano – Spain’s highest peak.
Popular tourist areas on Tenerife, part of the Canaries archipelago in the Atlantic Ocean, have so far been unaffected and its two airports have been operating normally.
Scorching heat and dry weather this summer have contributed to unusually severe wildfires in Europe, including in Spain’s La Palma island in July, and Canada. Blazes on Hawaii’s Maui island earlier this month killed more than 110 people and wrecked the historic resort city of Lahaina.
Scientists say climate change has led to more frequent and more powerful extreme weather events.