A high-pressure system over Europe is blocking cooler air from moving in. No significant cooldown is in sight until at least the Assumption of Mary, with temperatures in the interior expected to remain above 30 degrees.
Although many had hoped for an early end to the prolonged heat, the latest forecast maps bring no good news. A stable high-pressure system will strengthen over a large part of Europe, meaning Croatia will remain under the influence of sunny and very hot weather at least until the Assumption of Mary.
The UKMO model's calculation for Thursday, August 13, 2026, shows a pronounced ridge of high pressure over central and eastern Europe. Cyclonic systems remain trapped much further north and west, preventing frontal disturbances from breaking through to our region. As long as this pattern persists, a significant cold air intrusion is not possible.
Monday and Tuesday will be the most critical days. Zagreb is expected to reach 37 degrees. In Gospić, thermometers will show around 35 degrees, while Split will see temperatures ranging from 35 on Monday to 36 on Tuesday. Extreme values are forecast for Knin, where it could reach as high as 40 degrees on Tuesday. The east of the country will not be spared either, Osijek could hit 38 degrees on Tuesday.
Due to the heat wave risk, the State Hydrometeorological Institute (DHMZ) has issued its highest, red-level warning for the Split region for the start of the week.
From Wednesday, a slight drop in temperatures is expected. Zagreb should see around 33 degrees, falling to between 32 and 33 by Friday. In Gospić, temperatures will drop to 32 on Wednesday, then to 31 on Thursday and Friday. Although it will still be hot during the day, nights in Lika will be more comfortable, with morning lows potentially falling to 11 to 12 degrees in the second half of the week.
On the Adriatic, however, the situation will remain uncomfortable. Split will reach 37 degrees on Wednesday, with morning temperatures in that area staying between 26 and 29 degrees. After Tuesday, Knin will drop to 36 degrees, and Osijek to 32 to 34, which is a noticeable easing but not a true break from the heat.
For the Assumption of Mary itself, August 15, Zagreb is again forecast to see around 34 degrees, and Gospić around 33. DHMZ's forecasts maintain mostly sunny and very hot weather, with only rare local showers that cannot bring relief on a national scale.
The period after August 15 becomes more interesting. Some earlier model runs suggested the possibility of significantly cooler air descending toward central Europe around August 17 and 18. However, at that range, forecasts are still subject to significant changes. It will be the next runs of the forecast models that will show whether the heat wave will continue into the second half of the month or whether a more serious change in the weather will finally arrive.
