Firefighters work in front of flames during a wildfire in the Sierra de la Culebra in the Zamora Provence on Saturday June 18, 2022. AP
The worst damage has been in the northwest province of Zamora where over 25,000 hectares (61,000 acres) have been consumed, regional authorities said.
The blaze that started in Zamora's Sierra de la Culebra has forced the evacuation of at least 10 villages, although the drop in temperatures overnight has helped efforts somewhat. More than 500 firefighters are supported by water-dumping planes and helicopters in the sparsely populated area.
Authorities have been on alert for an outbreak of intense wildfires, with Spain sweltering under record temperatures at many points in the country for June. Experts link the abnormally hot period for Europe to climate change. Thermometers have risen above 40 degrees Celsius (104 degrees Fahrenheit) in many Spanish cities throughout the week _ temperatures usually expected in August.
A lack of rainfall this year combined with gusting winds have produced the conditions for the fires.
The spreading fire caused the high-speed train service from Madrid to Spain's northwest to be cut on Saturday. It was re-established on Sunday morning.
Military firefighting units have been deployed in Zamora, Navarra and Lleida.
There have been no reports of lives lost, but the flames reached the outskirts of some villages both in Zamora and in central Navarra. Videos shot by passengers in cars showed flames licking the sides of roads. In other villages, residents looked on in despair as black plumes rose from nearby hills.
In central Navarra, authorities have evacuated some 15 small villages as a precaution, as the high temperatures are not expected to drop until Wednesday.
They also asked farmers to stop using heavy machinery that could unintentionally spark a fire.
Wildfires are also active in three parts of northeast Catalonia: in Lleida, in Tarragona and in a nature park in Garaf, just south of Barcelona.