Wildfire meteorologist and researcher at the National Observatory of Athens, Theodoros Giannaros, spoke to protothema.gr about the extreme conditions Greece is facing due to the ongoing heatwave — and how they are making large wildfires harder than ever to control.

“Fires Are Mostly Man-Made — But Heatwaves Turn Them Into Monsters”

Mr. Giannaros emphasized that most wildfires are human-caused, whether due to negligence, intent, or faulty power infrastructure. However, once a fire starts, prolonged heatwaves create the ideal environment for it to spread rapidly and spiral out of control.

Wind Is No Longer Necessary for Wildfires to Spread

As Giannaros explained, the extreme heat of recent days has caused moisture levels to plummet, making vegetation more flammable. In many areas, humidity has dropped below 10%.

This means that even on calm days, when winds are weak or absent, fires can still spread easily and travel great distances quickly — making containment increasingly difficult.

“We’ve Lost the Nighttime Brake”

A key point raised by Giannaros is the disappearance of the natural advantage provided by nighttime. Under normal conditions, temperatures drop at night while humidity rises, giving firefighters a crucial window to control wildfires.

But during intense heatwaves, this cooling effect no longer happens.

“We’ve lost the brakes of the night,” he said, highlighting how nighttime temperatures remain high, and moisture doesn’t return. This is why fires now continue to burn aggressively even after dark — something that used to be rare.

What’s Needed for Recovery

Giannaros concluded that for vegetation to recover moisture levels and return to pre-heatwave resilience, several consecutive days of temperatures below 30°C are needed — both during the day and night. Without that, even small sparks can ignite uncontrollable wildfires in minutes.

With category 5 fire risk expected in the coming days and stronger winds on the way, he warned that conditions are now perfectly primed for disaster — and require extreme caution from both authorities and the public.