Croatia heatwave causes rising water temperatures and falling levels

Extreme summer heat in Croatia has led to significantly elevated water temperatures and declining water levels. At Lake Jarun in Zagreb, monitoring by the Institute for Waters revealed a record low water level drop of 250 centimeters. Surface water temperatures at the lake reached 31.1 °C, with temperatures remaining high even at depths of 1.5 meters (28.5 °C) and 6 meters (27.3 °C).

Regarding the physiological effects of warm water, Professor Marija Rakovac explains that water temperatures between 29 and 30 °C still provide a cooling effect to the human body, provided the water is cooler than the body's internal temperature. However, this cooling efficiency decreases as temperatures rise. The so-called thermoneutral water temperature, where cooling becomes significantly less effective, is cited in scientific literature as being between 34 and 35 °C. Experts also warn that staying in shallow water while directly exposed to the sun can cause body temperatures to continue rising.