Double waterspout between Koufonisia and Keros

Two waterspouts appeared simultaneously over the sea between Koufonisia and the uninhabited Keros, in the Small Cyclades, on the midday of Sunday, September 27, 2026. The phenomenon, which is not frequently observed in the area, was recorded in a video which was published on Facebook and was relayed by cyclades24.gr, describing it as an unusual sight. The report of cyclades24.gr was published at 16:50 and was updated at 19:47 the same day. According to what became known, no damage, injuries, or impact on maritime shipping in the area were reported, while the simultaneous appearance of two formations made the sight distinctive.

The waterspout is a rotating column of air and water vapor that forms over the sea surface, usually in conditions of unstable atmosphere, when cooler air moves over seawater that remains still relatively warm. This temperature difference creates vertical currents which, under certain conditions, begin to rotate and form the characteristic thin, funnel-shaped tube that connects the sea to the clouds. It is generally a short-lived phenomenon, with intensity significantly less than that of a typical land tornado, as it develops and dissolves in a relatively short time span without acquiring the duration or violence of land phenomena. The simultaneous appearance of two waterspouts, as recorded between Koufonisia and Keros, is even more unusual than the appearance of a single isolated phenomenon.

Koufonisia and the uninhabited Keros are located in the Small Cyclades, between Naxos and Amorgos, in a sea area served by small local shipping lines. More about the wider area can be found in the Naxos section, which also covers the Small Cyclades. Late September is a time when sea temperature remains still high from summer, while at the same time the first cold air masses of autumn reach the Aegean, a combination of conditions that favors the appearance of such phenomena in the sea area of the Cyclades. The same day, elsewhere in the Cyclades, intense rainfall and stormy winds were recorded, as described in the report on bad weather in Syros, an element that shows the general instability that prevailed in the Cycladic region that day.

The phenomenon between Koufonisia and Keros was short-lived and had no follow-up or impact, and so far nothing further has been announced about it, beyond what was already made known through the video and cyclades24.gr’s report. During such periods of unstable weather, with alternations of warm and cold air masses in the Aegean, general advice for caution is that small vessels in the area should monitor the weather forecast before departure, without this constituting an official authority warning for the specific case of Koufonisia and Keros.