Greece is heading into a heatwave over the coming days, with temperatures on a rising trend and the mercury forecast to reach 40C, or even 41C, in some areas.

The latest forecast data suggests the coming heatwave will be notable mainly for its duration rather than its intensity, according to current information. Under the most likely scenario, the heat will peak between 23 and 26 August.

Gradual rise, with highs of 41C in places

Temperatures will begin climbing gradually from Friday, 21 August, with mainland highs initially reaching 37 to 38C, and locally approaching 39C.

The heat is expected to become even more noticeable over the weekend, and by early next week some areas could see temperatures close to 40C or even 41C.

The highest temperatures are expected mainly in Central Macedonia, Thessaly, Central Greece, Aitoloakarnania (a region in western Greece) and the Peloponnese, though high temperatures will affect most of the mainland more widely.

The duration of the heatwave is particularly significant, with high temperatures expected to persist for several days. At the same time, limited overnight cooling could add to the strain on the body, making it harder to recover, particularly for elderly people, children and other vulnerable groups.

Weather on Friday, 21 August

Tomorrow, Friday 21 August, conditions are expected to be generally clear. Some cloud will build over the western mainland mountains around midday and in the afternoon, with local rain or showers possible.

Winds will blow mainly from the north, reaching up to 6 Beaufort in the Aegean.

Temperatures are expected to range as follows:

Western Macedonia: 15 to 32-34C

The rest of Macedonia and Thrace: 17 to 34-36C, locally up to 37C

Thessaly: 17 to 36-38C, locally up to 39C

Epirus: 17 to 34-35C

The rest of the mainland: 18 to 36-37C, locally up to 38C

The Ionian Islands: 19 to 34-36C

The Aegean islands and Crete: 16 to 31-33C, with the eastern Aegean islands locally reaching 36-37C

In the Aegean, winds will blow from the north at 3 to 5 Beaufort. In the southern seas, westerly to northwesterly winds will gradually take hold, at 4 to 5 Beaufort. In the Ionian, northwesterly winds will blow at 3 to 4, and locally up to 5 Beaufort.

Athens set for highs of 37C

Attica and Athens can expect sunshine, with some cloud building after midday. Winds will blow from the north at up to 3 Beaufort, and up to 4 Beaufort in eastern areas. Temperatures will range from 26 to 37C.

Thessaloniki will see some cloud, increasing over the mountains around midday. Winds will be light, blowing from the southeast during the hottest part of the day at 2 to 3 Beaufort.

Temperatures there will range from 25 to 33-34C.

When will the heat ease?

Temperatures will continue rising over the coming days, with mainland highs reaching 37 to 38C, while the eastern Aegean islands and the Dodecanese will locally touch 37C.

Current forecast data leaves room for a gradual easing of temperatures after 26 or 27 August. Although temperatures are expected to remain high, a further intensification of the heat towards the end of the month currently looks less likely.

At the same time, no significant rainfall is expected before the end of August, which is likely to keep drought conditions in place across many parts of the country.