More than 100 wildfires are stretching thousands of firefighters to the limit in northern Portugal. The country’s worst spate of fires in recent years is blamed for seven deaths since they spread out of control over the weekend.

Over the last few decades, wildfires have become more frequent, larger, and deadlier. Fires that were once considered rare and seasonal are now occurring year-round in many regions, with record-breaking consequences. This shift raises the question: are wildfires truly becoming deadlier, and if so, what are the reasons behind this alarming trend?

Firefighters tackling deadly wildfires in central and northern Portugal had doused the flames in the Aveiro district, one of the worst-hit, as of Thursday, and were focusing on eight large blazes still raging elsewhere.