A fire that started Friday evening in the central town of Almorox had already burnt at least 1,600 hectares, spilling over into the Madrid region and forcing the evacuation of a village, emergency services said.
Another blaze near the city of Toledo some 60 kilometres away also forced the evacuation of 22 residents, as water-dropping aircraft assisted firefighters on the ground amid strong winds, according to the regional government.
Meanwhile, a major blaze in the northeastern region of Catalonia had finally been contained and “was in the process of being stabilised,” the regional government said in a statement.
But it warned that a small part of the blaze remained of concern.
“Today the weather conditions continue to be extreme and the next hours will be critical and decisive, not just for this fire, but also for the rest of the territory,” it said.
The fires come as Europe is hit by a major heatwave, with temperatures in some parts of France reaching record highs.
Spain's weather agency said temperatures on Saturday would be above 36 degrees Celsius in a large part of the country, and would likely reach or go over 40°C in the centre including Madrid and south.
In parts of the northeast, meanwhile, they were expected to soar to 42°C.
Meteorologists blame a blast of hot air from northern Africa for scorching temperatures early in the European summer, but the heatwave is due to die down from Sunday.