Firefighters from the Unidad Militar de Emergencias (UME) tackle a forest fire near Artazu, Navarre province, Spain, June 19, 2022.
Firefighters from the Unidad Militar de Emergencias (UME) tackle a forest fire near Artazu, Navarre province, Spain, June 19, 2022. Reuters / VINCENT WEST

Emergency planes dumped water over part of rural western Spain on Monday to prevent flames reigniting from a huge wildfire that had ravaged about 30,000 hectares of land during a heatwave, the region's environmental service said.

The fire, which broke out last week during the country's worst mid-June heatwave in over 40 years, would be the largest in terms of surface area damage over the past two decades if estimates are confirmed, according to Environment Ministry data.

"Even though there are no flames anymore, the work continues," the service said. "Weather conditions are improving and ground and air teams are still at work."

Hundreds of residents of small villages who last week had to leave their homes as they were threatened by the flames were able to return, regional authorities said.

Temperatures across Spain were lower on Monday, and footage taken from a helicopter showed rainfall over the Sierra de la Culebra, a wooded mountain range near the border with Portugal that is known for its population of Iberian wolves.

Temperatures topped 40 degrees Celsius (104 degrees Fahrenheit) in many parts of Spain last week, their highest so early in the year since 1981, as record highs were also hit across other parts of Western Europe.

Firefighters backed by planes and military personnel were deployed around Spain to tackle a series of wildfires. Smaller ones than in the Sierra de la Culebra continued to smoulder on Monday to the east in Navarra and Catalonia.