Why Mega-Fires in the Mediterranean Are Becoming Uncontrollable

In the Mediterranean, large-scale fires are transforming landscapes and threatening populations far more than ordinary fires. A recent analysis of over 11,000 summer fires that occurred between 2008 and 2022 reveals that extreme weather conditions and prolonged drought play a decisive role in their spread. Medium and large fires account for the majority of fire outbreaks, but it is the very large fires and mega-fires that burn more than half of the affected areas. Although rare, these fires concentrate their devastation in a few areas such as Portugal, Spain, Sardinia, and Greece.

Mega-fires are distinguished by their ability to cross critical size thresholds. Their development depends mainly on the combination of violent winds, abnormally high nighttime temperatures, and vegetation already weakened by months of drought. Contrary to popular belief, it is not only the current weather conditions that fuel them, but also the long-term state of the soil and plants. Warm nights now prevent the usual cooling that once limited the spread of flames, allowing fires to expand continuously day and night.

Researchers have identified that soil temperature at night, wind strength, and the intensity of drought over three months are sufficient to predict up to two-thirds of mega-fires. These elements show that giant fires emerge when exceptional atmospheric conditions are added to an environment already primed by water scarcity and accumulated heat. Vegetation, even if it appears green, can be extremely flammable after periods of water stress.

The increase in heatwaves and tropical nights in the Mediterranean further exacerbates the risk. Prevention strategies must therefore target both forest management to reduce fuel continuity and the anticipation of periods when heat, wind, and drought persist. Without action, these extreme events, once exceptional, could become more frequent with climate warming. Combating these giant fires requires a better understanding of the interactions between weather, drought, and ecosystem conditions, as well as adapted measures to limit their spread.

Credits and Attributions

Primary Source

DOI: https://doi.org/10.1038/s44304-026-00197-5

Title: Megafires in Mediterranean Europe: the compound role of fire weather and drought

Journal: npj Natural Hazards

Publisher: Springer Science and Business Media LLC

Authors: Farzad Ghasemiazma; Marj Tonini; Paolo Fiorucci; Marco Turco