In the area around the town of Boiro, around 700 people have been evacuated after a fire broke out on Thursday.
There are no reports of injuries.
On Thursday, the temperature was measured at 40.9 degrees Celsius.
It has become cooler since then, but it is expected to be around 35 degrees in large parts of Spain on Saturday.
Climate change is making extreme weather, such as heat waves and droughts, more intense.
This in turn increases the risk of fires.
Since the beginning of the year, Spain has been hit by 366 forest fires, which have ravaged more than 233,000 hectares.
This is more than in any other country in Europe, according to Effis, an institution within the EU that monitors the fire situation in Europe using satellite images.