Although August is nearing its end, summer isn’t ready to retreat. A new surge in temperatures begins tomorrow, Friday, 21 August 2026, with thermometers expected to climb to 38°C across much of mainland Greece. The heatwave is forecast to peak over the weekend and extend into next week, pushing temperatures to 40°C in numerous regions — including Thessaly, Central Macedonia, the Peloponnese, and Attica.
A Prolonged and Potentially Dangerous Heat Event
According to the Hellenic National Meteorological Service (EMY), the main concern isn’t just the high temperatures themselves, but the duration of this extreme weather episode. The most intense period is expected from Saturday 23 to Tuesday 26 August. During those days, several inland areas — particularly in northern and central Greece — may see maximum temperatures reach or even exceed 40°C.
Regional Breakdown
On Friday, meteorologist Matina Berou of Star TV noted that highs will range between 36°C and 38°C across large parts of the country. Coastal and island areas will fare somewhat better, thanks to the meltemi winds — especially in the Aegean, where gusts may reach up to 6 on the Beaufort scale. These breezes are expected to temper the heat slightly in places like the Cyclades (29–30°C), Crete (33–34°C), and the Ionian islands (34–36°C). In contrast, eastern Aegean islands and the Dodecanese could still hit 36–37°C.
Saturday’s forecast shows temperatures climbing further: up to 38–39°C in Thessaly, while Sunday may bring isolated readings of 40°C. Highs in Attica are expected to reach 38°C, with similar conditions anticipated across Central Macedonia and the Peloponnese.
Nighttime Heat Adds Risk
What makes this heatwave especially taxing is the lack of nighttime relief. Minimum temperatures are projected to remain unusually high — between 27°C and 28°C — significantly limiting the body’s ability to recover. Combined with elevated humidity levels, this raises the risk of heat stress, particularly for vulnerable groups such as the elderly and young children.
Wind and Skies
Friday’s weather will be generally clear, with only brief, localized cloud cover over western mountainous areas during afternoon hours — where isolated showers or thunderstorms are possible. Winds will blow from northerly directions: 3–5 Beaufort across western mainland areas, increasing to 6 Beaufort locally in the Aegean Sea.
This extended hot spell is expected to persist well into next week, with temperatures remaining up to 7°C above seasonal norms — underscoring the exceptional nature of this late-summer heat event.