Spain's weather agency warned the public on Monday to be "cautious" of the "very high or extreme fire danger."

This year is turning into one of the worst fire seasons in recent memory in Europe. Firefighters are struggling to contain out-of-control wildfires in western Spain and Portugal.

Firefighters in Spain, Portugal and Greece battled ongoing wildfires Friday, an important religious holiday in all three countries, as persistent hot, dry conditions challenged efforts to contain the blazes.