The blaze started at the military base of Cerro Muriano, Córdoba in the Andalusia region of Spain.
Locals and tourists are now being warned that the fire has spread outside the military exclusion zone.
The fire was reported by local news at around 9pm local time Friday night.
It is not yet clear what started it.
Andalusia is a large autonomous region of hills, rivers and farmland bordering Spain's southern coast.
It is located between two popular holiday destinations loved by Brits - Malaga and Seville.
It comes after authorities warned of possible wildfires, melting pavements and weather alerts in Europe as it becomes the fastest warming continent on Earth.
Comment: Noted; however very hot summer temperatures are typical in these regions.
Temperatures have been rising at roughly twice the global average in some countries.
During high temperatures, experts have warned people to be cautious, drink plenty of water and avoid going outside during the hottest hours of the day.
Forest fires have been reported this week in Albania, near the border with Greece, as well as in Bosnia and Italy.
Comment: In recent years a large portion of these fires have been revealed to have been started by arsonists.
Several blazes also raged Thursday in Greece's southern Corinth area and on the eastern Aegean Sea island of Lesbos.
In Spain, areas such as Seville and Badajoz are likely to experience extreme temperatures next week as mercury levels rise above 45C.
Comment: There's been a number of fires and explosions at Western military manufacturers, and bases, of late, and one wonders just what exactly is the cause? It could be the West's attempts to ramp up production is leading to accidents, or, since Russia has also suffered a relentless sabotage since starting the SMO, it may be that the question is: who is to blame? At least in Russia's case the allegiance and purpose of the perpetrators is a little more obvious: