The fires have destroyed more than 10,000 acres of land on Tenerife and La Gomera -- roughly 100 kilometers (62 miles) off the coast of Morocco -- since they first broke out more than a week ago. At least 5,000 people were forced out of their homes and lodging over the weekend, though many were later allowed to return.
By Sunday afternoon, 10 towns on La Gomera and eight on Tenerife were put off limits as firefighters rushed to contain fires. The flames also threatened some of Spain's most treasured national parks, including Garajonay National Park, a Unesco World Heritage Site famed for its prehistoric woodland that scientists believe dates back some 11 million years to the Tertiary Period.
Officials have said it could take at least three decades for burnt portions of the reserve to recover.
Roughly 1,000 tourists and residents were evacuated from Valle Gran Rey in western La Gomera by boat over the weekend as authorities feared fires could engulf the town. Some 3,000 others were gathered at the town's port area on Monday monitoring developments, according to the regional government.
Each year, about five million tourists visit Tenerife, the main island, and some 1.5 million of them come from Great Britain. The Foreign Office has warned tourists to monitor the current situation closely and stay in touch.
"There are reports of forest fires on the island of Tenerife around the area of El Tanque, Ruigomez, San Jose de los Llanos, El Palmar, Teno Alto, Lagunetas, Valle de Arriba, Erjos, Masca and Las Portelas," the office said. "There are also reports of forest fires on the island of La Gomera around the areas of Las Hayas, El Contadero, El Cruce de las Hayas, Los Manantiales, Chipude, Arure, Banda Las Rosas, Valle Gran Rey and El Cercado."
The Foreign Office advised British citizens to check the Canaries' government website for updates.
Though some roads remained closed Monday, flights in and out of Tenerife continued as normal, and most tour operators reported little disruption.
"Resorts have not been affected by the fires, though as a precaution, tour operators have suspended some inland excursions on Tenerife," Sean Tipton of Britain's ABTA travel industry group told the Press Association, adding that some tourists were offered alternative hotels.
A dry winter followed by a scorching summer heat wave left the archipelago at high risk of fires. The current blaze broke out more than a week ago but was fanned by warm winds over the weekend.
Javier Gonzalez Ortiz, minister of economy, finance and security of the Canary Islands, said at a press conference Monday: "There is better news coming from Tenerife than from the island of La Gomera."
Ortiz noted that while the fire on Tenerife has been stabilized, the one on La Gomera has not. He called on Madrid to send more resources to help combat the problem before it gets any worse.