Eastern mainland Greece is set to experience one of the most intense heatwaves of the year on Wednesday, July 22, 2026, with temperatures expected to reach 43 degrees Celsius in some areas. The heat surge comes alongside an extreme wildfire risk across much of the country, while emergency protective measures have been enacted for workers, including a mandatory work suspension.
Read also: Heatwave alert: Traffic bans in Seich Sou and Halkidiki — Samaria Gorge closed
Where the heatwave will hit hardest
According to an emergency bulletin issued by the Hellenic National Meteorological Service (EMY), the regions expected to bear the brunt of the heatwave are Thessaly, eastern Central Greece, and the eastern Peloponnese.
According to the EMY emergency bulletin, the distribution of maximum temperature values is as follows:
- Thessaly: Temperatures will reach 41 to 42 degrees Celsius, with isolated readings of up to 43°C.
- Eastern Central Greece & Attica: Temperatures will range between 41 and 42 degrees, while the Athens basin specifically will experience stifling heat with the thermometer hitting 40 to 41 degrees.
- Eastern Peloponnese: Values in the order of 41 to 42 degrees Celsius are expected.
Kolydas warning: The areas under greatest heat stress over the next 48 hours
Meteorologist Thodoris Kolydas is warning of locally elevated heat stress on Wednesday, particularly for those working or active outdoors. Based on meteorological data and forecast maps, heat stress will be most pronounced across parts of mainland Greece — primarily in Thessaly, areas of Central Greece, parts of the Peloponnese, and locally in Attica. The highest values on the heat stress index appear mainly in inland and enclosed continental areas, where the combination of heat and humidity worsens conditions. Notable examples include Kalamata, Chalkida, Larissa, and Heraklion, with values near or slightly above the thresholds for moderate to locally elevated stress. In Attica, the stress is not uniformly distributed but is more intense in the more inland and enclosed parts of the region. However, on Thursday, July 23, a clear drop in the heat stress index is expected across almost the entire country, with improvement most visible in northern Greece, eastern mainland areas, and Attica.
Kolydas’s post
“A SCIENTIFIC APPROACH
Without replacing the official role of the EMY, and with a purely research-based approach, the two #WBGT forecast maps provide a useful general picture for the next two days.
Wednesday 22/07
The first map shows that heat stress will be more pronounced across parts of the mainland, primarily in Thessaly, areas of Central Greece, parts of the Peloponnese, and locally in Attica. The highest values appear mainly in inland and enclosed continental areas, where the combination of heat and humidity pushes the index higher. Values near or slightly above the moderate-to-locally-elevated stress thresholds stand out, with Kalamata, Chalkida, Larissa, and Heraklion as characteristic examples.
In Attica, the inset shows that the stress is not uniform but appears more intense mainly in the more inland and enclosed sections of the region.
Thursday 23/07
The second map shows a clear drop in the heat stress index across almost the entire country. The shading is noticeably milder and most areas are moving to lower WBGT levels. This decline is visible in northern Greece, the eastern mainland, and in Attica, where the inset shows a marked weakening of heat stress. Only a few more southerly or easterly areas retain locally marginally higher values, without, however, forming a picture of widespread elevated stress.
Conclusion
Overall, the maps suggest that Wednesday 22/07 is the day of greatest interest in terms of heat stress, while Thursday 23/07 sees widespread improvement.
Based on this specific forecast assessment, there is no indication of a widespread extreme heat stress episode across the country; however, Wednesday does show locally elevated levels of stress, primarily for those working or active outdoors.”
ΜΙΑ ΕΠΙΣΤΗΜΟΝΙΚΗ ΠΡΟΣΕΓΓΙΣΗ
Χωρίς να υποκαθιστούμε τον επίσημο ρόλο της ΕΜΥ και με καθαρά ερευνητική προσέγγιση, οι δύο χάρτες του προγνωστικού #WBGT δίνουν μια χρήσιμη γενική εικόνα για το επόμενο διήμερο.
Τετάρτη 22/07
Ο πρώτος χάρτης δείχνει ότι η θερμική καταπόνηση θα είναι… pic.twitter.com/ofTP3dvTh5— Theodoros Kolydas (@KolydasT) July 21, 2026
Extreme wildfire risk and state of alert
Civil Protection, the Fire Service, and the Armed Forces are being placed on high alert due to the enormous wildfire risk on Wednesday, July 22. The Civil Protection Risk Assessment Committee has characterized the day as exceptionally challenging, with pyrometeorological conditions creating an environment of extreme danger. The combination of very high temperatures, strong winds, and particularly low humidity levels is creating conditions highly conducive to the ignition and rapid spread of wildfires. The Risk Assessment Committee and the Civil Protection Coordination Body met today in the presence of the Minister for Climate Crisis and Civil Protection, Evangelos Tournas.
Areas under category 5 alert status
According to the Wildfire Risk Forecast Map issued by the General Secretariat for Civil Protection, an Extreme Wildfire Risk and Category 5 Alert Status has been declared for the Region of Attica, the Regional Units of Boeotia and Phthiotis in Central Greece, and the Regional Units of Argolis and Corinthia in the Peloponnese. A Very High Wildfire Risk at category 4 has been declared for the Region of the Peloponnese (Arcadia and Laconia), the Region of Western Greece (Aetolia-Acarnania and Achaea), the Regional Units of Phocis and Euboea, the Region of Thessaly, the Regional Units of Kilkis and Thessaloniki in Central Macedonia, and the Regional Unit of Rhodes.
Minister for Climate Crisis and Civil Protection Evangelos Tournas urged the public to remain vigilant, calling on citizens to follow official guidelines and avoid any activities that could potentially start a fire. He stressed that the entire Civil Protection Mechanism is being placed on standby — up to maximum readiness — depending on the risk level in each area. Minister Tournas warned that conditions are reminiscent of other catastrophic events, stating: “We will have strong westerly and northwesterly winds, which will become katabatic on the eastern side and are similar to the phenomenon we experienced in Mati. Fire tomorrow is absolutely prohibited because conditions will be such that it will be very difficult to tackle any incident at the first stage.“
Fire Service units, the Armed Forces, Forestry Services, Security Forces, and first- and second-tier Local Government authorities, supported by EKAV (National Emergency Medical Service) and volunteer teams, will make every possible effort to respond to incidents.
Mandatory work suspension due to heatwave
The heatwave has triggered emergency protective measures for private sector workers, according to an announcement by the Ministry of Labour and Social Insurance. On Wednesday, July 22, 2026, a mandatory suspension of outdoor work from 1:00 p.m. to 5:00 p.m. has been imposed due to the exceptionally high temperatures expected. The circular signed by the Secretary General for Labour Relations, Nikos Milapidis, stipulates that employers are obliged to take all necessary technical and organizational measures to protect workers from heat stress. The measure applies to eastern Central Greece, Thessaly, the eastern Peloponnese, and the entire region of Attica. Between 1:00 p.m. and 5:00 p.m., the performance of outdoor manual labor on technical and construction projects, building sites, shipyard repair zones, as well as the delivery and transportation of products using two-wheeled vehicles, scooters, or roller equipment, is prohibited. The mandatory work suspension applies to all workers regardless of their employment type, including those operating through digital platforms. Through these measures, authorities aim to protect workers from the extreme conditions expected during the heatwave.
