The meltemi is one of the most defining features of the Greek summer, with powerful northern winds making their presence felt primarily across the Aegean Sea. But just how intense was this phenomenon during this year’s summer, and how many days did winds actually reach high intensities?
Meteorologist Nikos Kanteres gives parapolitika.gr his full assessment of this summer’s wind activity, revealing that a total of 16 days with strong meltemi winds were recorded, with winds reaching up to 9 Beaufort on three separate occasions.
Despite their intensity, however, the number of days is not considered unusually high. On the contrary, as the experienced meteorologist explains, this summer’s pattern can be described as fairly normal.
Weather: The 16 days of strong meltemi winds
The presence of the etesian winds — the meltemi’s official name — gradually intensified as the summer progressed. According to data provided by Mr. Kanteres, June saw just one day with winds of 7 to 8 Beaufort, while July recorded four such days, three of which occurred toward the end of the month.
The highest frequency was recorded, as expected, in August, which brought nine days of strong winds. In total, across the entire summer, the days with strong meltemi winds reached 16.
“That’s not a lot,” notes Mr. Kanteres, summing up this year’s picture. Of those days, winds reached 9 Beaufort on three occasions — without, according to him, causing any significant disruption to maritime traffic.
Why are they called “etesians”?
While the word “meltemi” has become the everyday term for these winds, their proper Greek name is “etesies” (etesians).
According to Mr. Kanteres, this name is linked to the fact that these winds return every year during the summer season. Their observation and description dates back approximately 2,500 years, to the time of Aristotle.
The etesian winds are divided into two distinct periods. The first to appear are the so-called “prodromos etesies” (forerunner etesians), which blow during June and July, followed by the “kyrioi etesies” (main etesians), which make a stronger impression in August.
This pattern was clearly reflected this year as well, with the majority of strong meltemi days recorded during the final month of summer.
What determines their path
The meltemi does not blow in the same direction across the entire Aegean. Wind patterns shift depending on the region.
According to Mr. Kanteres, in the Northern Aegean — from the area around Lemnos toward the Euboean Gulf and Attica — winds blow primarily from a north-northeastern direction. Over the Cyclades and Crete, they shift to northerly winds, while further toward the Dodecanese they take on a north-northwestern direction.
Unlike the Aegean, the Ionian Sea is not affected by the same meteorological mechanism in the same way.
How the meltemi forms
The key factor driving both the appearance and the intensity of the meltemi winds is the difference in atmospheric pressure between the Balkans and the broader Eastern Mediterranean region.
During summer, when an anticyclone and high pressure dominate over the Balkans, a thermal low-pressure system simultaneously develops over the Middle East and Cyprus.
The pressure difference between these two areas creates the characteristic northerly airflow across the Aegean. The greater the difference in atmospheric pressure, the stronger the winds become.
In fact, as Mr. Kanteres points out, there is a practical rule of thumb used to estimate wind intensity: the difference in atmospheric pressure between Athens and Rhodes serves as an indicator of how many Beaufort can be expected across the Cyclades.
What 8 and 9 Beaufort mean at sea
Wind intensity is measured on the Beaufort scale, which divides wind strength into 12 grades and links each grade to specific sea conditions.
At 8 Beaufort, the sea is classified as rough, while at 9 Beaufort it is classified as very rough, with a significant increase in wave height and considerably more challenging conditions for navigation.
For conditions across Greek waters, the Hellenic National Meteorological Service issues daily marine weather bulletins by sea area, as well as special alerts when deemed necessary.
This year’s overall assessment shows that despite the days when the Aegean faced very strong winds, the total presence of the etesian winds remained, according to Mr. Kanteres, at fairly normal levels — confirming once again one of the most distinctive meteorological features of the Greek summer.
