The State Hydrometeorological Institute has issued a red alert for the entire interior and the northern Adriatic. Relief is not expected until the weekend, and historical data reveals that heatwaves are becoming longer and more intense.
Croatia is today at the peak of a heatwave that has brought unbearable temperatures. The State Hydrometeorological Institute (DHMZ) has issued its highest, red alert for the entire interior and the northern Adriatic, while the rest of the country is under an orange Meteoalarm. In Slavonia, Baranja, and Syrmia, the mercury is climbing to 40 degrees Celsius, and conditions are hardly more pleasant elsewhere.
According to data from sources, temperatures in central Croatia range from 37 to 39 °C, while Dalmatia will see between 33 and 38 °C. The northern Adriatic is expected to reach 32 to 37 °C. The morning brought milder values, from 17 to 21 °C inland and between 22 and 26 °C on the coast. The sea is also exceptionally warm, with temperatures from 26 to as high as 29 °C.
The next two days offer no respite. Daytime temperatures will continue to range between 35 and 40 °C. In mountainous areas, Lika, and the interior of Istria and Dalmatia, there is a slight chance of local afternoon showers, but the real change in weather is expected from Friday.
Then, cooler and more unstable air is expected to flow from the north towards Croatia, bringing relief but also potentially severe weather with showers and thunderstorms. By the weekend, temperatures inland will drop to a more pleasant 30 °C, while the Adriatic will remain hot, around 35 °C. DHMZ advises avoiding prolonged sun exposure between 10 a.m. and 5 p.m., drinking plenty of fluids, and eating lighter meals until then.
While the country grapples with the current heatwave, the 45th anniversary of the highest temperature ever officially recorded in Croatia is being marked. On August 4, 1981, a scorching 42.8 °C was recorded in Ploče. That record was set under extreme conditions that literally deformed infrastructure.
On the railway line from Ploče towards Mostar, tracks buckled over a stretch of 300 meters. Passengers on the critical section towards Sarajevo were transported by buses, and locals helped unload livestock from halted trains. Asphalt melted at around 70 degrees, and the hoods of cars parked in the sun heated up to 90 °C.
Interestingly, although temperatures above 40 degrees have been recorded in Croatia more than 50 times according to DHMZ data, before 1981 there were only four such cases. All occurred during the heatwave of July 1950: Karlovac recorded 42.4 °C, Osijek 40.3 °C, and Zagreb's Maksimir and Grič stations recorded 40.4 °C and 40.3 °C, respectively.
Although the absolute record from Ploče has stood for nearly half a century, climatologists warn that climate change is not primarily manifested through record-breaking, but through increasingly longer periods of extreme heat. The data confirms this. In Makarska, in July 2025, temperatures exceeded 30 °C on 28 days, while Ploče had 23 such days in August of the same year.
Tropical nights, during which temperatures do not drop below 20 °C, are becoming a particular problem. In August 2025, Lastovo and Dubrovnik each recorded 28 such uncomfortable nights. For comparison, world records are even more extreme. In Syracuse, Sicily, on August 11, 2021, a temperature of 48.8 °C was measured, while the absolute record is held by Death Valley in California, where 56.7 °C was recorded on July 10, 1913.
Increasingly intense heatwaves are changing daily life. Air conditioning has become a necessity, directly impacting electricity consumption. The Croatian transmission system operator recorded a record hourly electricity consumption on July 17, 2024, precisely during a strong heatwave. This creates a vicious cycle: the longer and more intense the heat, the greater the need for cooling, and thus the greater the strain on the energy system.
