Will September bring cooler weather to Croatia?

According to the ECMWF seasonal forecast, September is expected to be warmer than average, so no real relief is expected for now, although the first severe storms are possible.

What precipitation is expected during autumn?

The precipitation forecast is uncertain, but there is a scenario of rapid alternation between dry periods and short, intense downpours that could cause flash floods.

Will the entire autumn be warm and sunny?

Although above-average temperatures are predicted, this does not guarantee stable weather. More frequent cold air intrusions from northern Europe are expected.

What is this long-range forecast based on?

The forecast was produced by the European Centre for Medium-Range Weather Forecasts (ECMWF) based on 51 simulations, which show the probability of temperature and precipitation deviations from the average.

Croatia

Autumn Forecast Leaves No Room for Hope: Croatia Faces Continued Warmth

A.G. · Prije 4h | 2 min

Seasonal models from the European Centre for Medium-Range Weather Forecasts (ECMWF) predict above-average temperatures to persist through September, October, and November, with an increased risk of extreme rainfall following prolonged drought.

Summary

ECMWF predicts that September, October, and November in Croatia will be warmer than average.
Summer temperatures could extend, especially along the Adriatic, with above-average sea temperatures.
There is an increased risk of intense downpours after drought, which could lead to flash floods.
The forecast is based on 51 simulations and cannot predict weather for a specific day, only the trend of deviations.

As Croatia grapples with yet another heatwave and prolonged drought, there are currently no signs that summer will soon relent. The latest seasonal calculation from the European Centre for Medium-Range Weather Forecasts (ECMWF) model, based on 51 simulations, indicates that the remainder of summer and a significant portion of autumn could see temperatures above the norm.

September Brings No Real Relief

If you were hoping for a significant cooldown with the arrival of September, seasonal models currently offer little reason for optimism. ECMWF also expects September to be warmer than average. This implies that summer heat could linger longer than usual, especially along the Adriatic coast, with the sea potentially warmer than normal.

Regarding precipitation, forecast confidence is considerably lower. Models show a wide range of possible outcomes, opening the door for intrusions of moist Atlantic air and the formation of stronger cyclones. Therefore, September, although warmer, may also bring the first serious storms after long dry spells. Temperatures should gradually decline but remain above typical values.

Warmer Autumn and Threat of Extreme Downpours

The warmer signal does not disappear after September. According to ECMWF, October and November could also be warmer than average. However, this does not mean the entire autumn will be stable and sunny. On the contrary, cold air intrusions from northern Europe may become more frequent during autumn.

One possible scenario is a rapid alternation between long dry periods and short but very intense rainfall. This pattern has become increasingly common in recent years across the Mediterranean, Croatia's Adriatic coast, and the Balkan interior. Particularly concerning is the possibility of heavy downpours following prolonged drought, which could heighten the risk of flash floods and other consequences of extreme weather events.

The ECMWF seasonal model predicts that much of central and southeastern Europe could see above-average temperatures during summer and autumn, placing Croatia right at the heart of the region affected by this prolonged warming trend.