Croatia Sizzles at 40°C: First Time This Summer
The Osijek-aerodrom station recorded exactly 40 degrees on Thursday. The heatwave shows no signs of letting up, but meteorologists forecast a change as early as Friday.
The Osijek-aerodrom station recorded exactly 40 degrees on Thursday. The heatwave shows no signs of letting up, but meteorologists forecast a change as early as Friday.
Croatia reached the 40-degree Celsius mark for the first time this summer on Thursday, August 6, 2026. According to data from the State Hydrometeorological Institute (DHMZ), at 5 PM the measuring station at Osijek-aerodrom recorded exactly 40.0°C, marking the peak of a heatwave that has been ongoing for two weeks. Alongside the unbearable heat, air pressure stood at 1011.4 hPa, and relative humidity was a mere 20 percent.
It was also very hot in the rest of Slavonia. At the Gradište and Osijek-Čepin stations, temperatures reached 38.0°C, while Slavonski Brod recorded 37.9°C. Zagreb, at Maksimir, sweltered at 36.7°C. In Opatija, temperatures were the most pleasant, reaching 30.5°C. Earlier in the day, at 3 PM, the heat peaked in Valpovo and at Zagreb's Grič with readings of 38.8°C.
According to DHMZ data reported by Index.hr, at 5 PM temperatures ranged from 38 degrees in Osijek, Daruvar, Slavonski Brod, and Gradište, through 37 degrees in Varaždin, Zagreb, Karlovac, Sisak, and Knin, to 35 degrees in Gospić and Makarska. On Rab and in Šibenik, 34 degrees were measured, in Rijeka and Split 33, and in Zadar, Hvar, and Dubrovnik 32 degrees. In Pazin and on Zavižan, at the same time, 26 degrees were recorded, the lowest temperatures.
Although 40°C is an impressive figure, it is not the highest temperature in Croatia this year. That title still belongs to Knin, where 41.0 degrees was measured on June 30, 2026. Today's temperature in Osijek thus ranks as the second highest recorded in 2026.
DHMZ issued a very high heatwave risk warning for Thursday for Osijek, Zagreb, Karlovac, Gospić, Knin, Rijeka, Split, and Dubrovnik. This is the highest alert level, due to the potential health impacts of extreme heat. The elderly, young children, chronic patients, and outdoor workers are particularly at risk. Citizens are advised to avoid the sun during the hottest part of the day, drink plenty of fluids, and cool their living spaces.
The Meteoalarm will also be in effect for the entire country on Friday, August 7. The Rijeka, Split, and Dubrovnik regions will remain under a red alert due to exceptionally high daytime temperatures and warm nights. For the Osijek, Zagreb, Karlovac, and Gospić regions, a yellow Meteoalarm remains in place as daytime temperatures will still exceed 30°C, with nighttime lows above 20°C. The very high heatwave risk for Rijeka, Split, and Dubrovnik remains in effect until Monday, August 10, 2026.
The long-awaited weather change arrives on Friday. Conditions will be more unstable, with more clouds, occasional rain, and thunderstorms, which could be locally strong. Winds will be moderate, occasionally strong, from the north and northeast, while the Adriatic will see a moderate to strong bora. Gusts near the Velebit foothills may reach storm force, while in Dalmatia, northwest and southwest winds will pick up in the afternoon.
Although a refreshment is coming, temperatures will remain high. Morning lows will range from 18 to 23°C, and along the Adriatic from 23 to 28°C. Daytime highs will reach 28 to 33°C, with 34 to 37°C in the east and along the coast. Over the weekend, inland temperatures will gradually rise again after a brief cool-down, while the Adriatic will stay mostly sunny and very hot, with warm and locally very warm nights.
