The State Meteorological Agency (AEMET) has issued a map showing the probability of fires across different parts of Spain.
Almost the entire country has been designated as at 'extreme' or 'very high' risk, according to national daily ABC.
The only exceptions are the Mediterranean coast, parts of the Pyrenees, certain areas in Cantabria and the Atlantic coast.
On the Canary Islands, the larger islands are considered to be in the most danger.
Seventeen provinces have been put on alert due to high temperatures in central and southern Spain, where temperatures are expected to once again climb above 40ºC.
Storms are also expected in the north-east.
Fires have already blazed across some areas of Spain this summer, leading to forced evacuations in Galicia and Majorca.