Greece is preparing for its first significant heat wave of the summer, beginning today, Wednesday, June 25. It is expected to last for three days.
Warm air masses originating from the African coasts will push temperatures to extreme highs, with the mercury anticipated to “climb” as high as 42C (108F) in several regions.
Meteorologist Giorgos Tsatraphyllias confirmed that these warm air masses will affect Greece until Friday, June 27, marking the start of this summer’s initial heat wave. Vulnerable groups are strongly advised to take all necessary protective measures, as Thursday and Friday are projected to be the most dangerous days.
Heat wave’s peak temperatures and affected areas in Greece
The highest temperatures, reaching 42C to 43C (108F to 109F), are forecast for Friday, June 27, particularly in the closed plains of Central Macedonia and Thessaly.
On Thursday, regions such as Aitoloakarnania, Serres, Kilkis, and Thessaly could see temperatures hit 41C (106F). By Friday, the 41C mark will be concentrated in Thessaly and Boeotia. Nighttime temperatures on Friday are also expected to remain high, exceeding 30 C (86F) in major cities like Athens and Thessaloniki.
Athens:
Wednesday: 38
Thursday: 39−40
Friday: 40−41
Saturday: 37−38
Sunday: 34
Thessaloniki:
Wednesday: 37−38
Thursday: 38
Friday: 38−39
Saturday: 35−36
Sunday: 35
According to meteorologist Kolydas, the heat wave will be short-lived and of moderate intensity, with Friday marking its peak. Starting on Saturday, June 28, temperatures are expected to drop significantly by ten to twelve degrees, making the heat much more bearable. Current forecasts do not show any other temperatures exceeding 40C.
Related: What to Know Before Traveling to Greece During a Heatwave
Atmospheric conditions and the “urban heat island” effect
While temperatures soar, the atmosphere is expected to remain clear of dust due to northerly winds. However, Northern Greece may experience some afternoon storms or even thunderstorms on Friday.
A significant concern for the country’s major urban centers over the next three days is the urban heat island phenomenon. This effect describes how temperatures within cities are noticeably higher than those in surrounding rural areas. This is largely attributed to human factors, as urban development replaces natural environments with heat-absorbing materials such as cement and asphalt, which retain and re-emit large amounts of solar radiation throughout the day.
Dense construction also traps hot air and hinders the entry of cooler breezes, while reduced green spaces diminish natural cooling from plant transpiration. Anthropogenic activities, such as air conditioning use and car emissions, further exacerbate the problem by releasing additional heat into the atmosphere. Authorities urge residents to remain informed on weather updates and follow guidelines to protect themselves during this period of extreme heat.
Related: The Deadly 1987 Heatwave in Greece That Left 1,300 Dead