September the 2nd, 2026 – The September sea temperature records have been broken in both Split and Komiža, with strong warmth still beating down on the Croatian coast.
The sea was unusually warm along a large part of the Croatian coast on the first day of September. According to DHMZ data, at 14:00 yesterday, the temperature measured in Split was 28.0 degrees, in Komiža 28.2 degrees, and near Dubrovnik it also stood at 28.2 degrees. Index reports that the sea is even warmer on Mljet. In Malo jezero at 2 p.m. as much as 30.2 degrees was measured, in Veliko jezero 29.9 degrees, while on the open sea near Mljet the temperature was 28.8 degrees.
september records have been broken in split and Komiža
Data from both Split and Komiža is particularly interesting. According to the DHMZ bulletin for September 2025, the previous absolute September maximum in Split was measured at 27.3 degrees, measured on the 2nd of September 2015. In Komiža, the record was also 27.3 degrees, set on the 2nd of September 2024. Yesterday afternoon’s 28.0 degrees in Split is therefore 0.7 degrees higher than the previous September record, while Komiža with 28.2 degrees exceeded the old record by as much as 0.9 degrees. These are operational DHMZ data, so the final values will be confirmed after data processing. For comparison, during the whole of September last year the highest measured value in Split was 25.0 degrees, and in Komiža 24.6 degrees. Even in the very warm September of 2024, the maximum recorded in Split was 27.0 degrees. The average sea temperature in Split that September was 24.0 degrees, a full 1.7 degrees above the climatic average for the period 1991–2020.
a mere 1.4 degrees lower than the absolute record for that particular station
Yesterday afternoon’s 28 degrees in Split is only 1.4 degrees lower than the absolute record for that specific station. In Split back on the 15th of July 2024 a temperature of 29.4 degrees was measured. Values from Mljet should not be directly compared with the long-term series from Split and Komiža. Malo and Veliko jezero are measured by automatic sensors and aren’t part of the same long-term series of the four stations – Rab, Split, Hvar and Komiža – that DHMZ uses in monthly analyses of September sea temperatures. Surface sea temperature at the classic stations is measured approximately 30 centimetres below the surface.
