According to weather forecasts, a prolonged heatwave is approaching Greece, set to last from Sunday (July 6, 2025) through Thursday, with temperatures expected to reach as high as 43 degrees Celsius. Meteorologist Klearchos Marousakis explained the phenomenon behind the upcoming heatwave: ‘A field of high atmospheric pressure covers much of western and central Europe, resulting in the transportation of extremely hot air masses from the coasts of North Africa into these regions.’ He further described the heat dome effect: ‘Imagine an atmospheric circulation shaped like a bell or dome where very hot air enters at the lower part and becomes trapped inside, unable to release into higher levels of the troposphere. In scientific terms, this occurs because within a high-pressure system, the atmospheric air moves downward, accumulating hot air in the lower layers of the troposphere.’
Marousakis continued: ‘Cold air tries to move around the dome with the help of low-pressure systems but cannot penetrate inside—what we refer to as an atmospheric mountain.’ He noted that ‘From the weekend onward, this dome or heat dome—as we also call it—will shift toward our region, transporting the intense heat further east.’
He added: ‘Between Monday and Thursday, mercury levels will climb above 40°C locally. The most challenging days appear to be Wednesday and Thursday, with temperatures possibly reaching up to 42°–43°C.’
He emphasized that ‘This heatwave seems likely to end in a dramatic and dangerous manner. On Thursday, a cold front descending from the northern Balkans will significantly strengthen the northwesterly winds, potentially reaching gale force. Therefore, our focus must be on:
– The extreme fire risk
– Dangerous thunderstorms in northern areas due to the sudden change in conditions.’
He urged citizens to remain highly cautious in the coming days due to the combination of extreme heat, heightened wildfire danger, and potentially severe storms marking the end of the heatwave.