Thessaloniki wildfire sparks toxic smoke cloud across northern Greece
A large wildfire erupted on the night of 4 July in the Oraiokastro area near Thessaloniki, Greece. The fire ignited in forested land and quickly spread to a nearby recycling plant, destroying three warehouses and several factories that processed plastics, paper, oil‑derived products and textiles. Over 160 firefighters, 50 fire‑engine vehicles and aerial units fought the blaze, using water and the “fire‑triangle” technique of smothering with soil to cut off oxygen.
The combustion of industrial and plastic waste generated a dense toxic plume that covered Thessaloniki and drifted westward with north‑western winds. Authorities reported hazardous substances in the smoke, including volatile organic compounds, benzene, dioxins and other carcinogenic chemicals, as well as high concentrations of fine particulate matter (PM₂.₅, PM₁₀). The cloud was forecast to move southward, reaching parts of Central Greece, the Attica region and, according to AtmoHub simulations, the island of Crete.
Local officials ordered the evacuation of several villages and advised residents—especially the elderly, children and people with respiratory conditions—to stay indoors, keep windows and doors closed, wear high‑filtration masks and use air‑conditioning with recirculated air only. A 76‑year‑old man was detained on suspicion of causing the fire after police said he drove under the influence and sparked the blaze.
The incident follows a heatwave that pushed temperatures above 40 °C in parts of Europe and has contributed to a broader wave of wildfires across Spain, France, Portugal and Greece, prompting travel advisories for tourists and the cancellation of spectators at a stage of the Tour de France.