Weather

Croatia’s climate is determined by its position in the northern mid-latitudes and the corresponding weather processes on a large and medium scale. The most important climate modifiers over Croatia are the Adriatic and the Mediterranean, the Dinarides’ orography with their form, altitude and position relative to the prevailing air flow, the openness of the north-eastern parts to the Pannonian plain, and the diversity of vegetation. Therefore the following three main types of regions – with continental, mountain and maritime climate, prevail in Croatia.

The most common are Köppen and Thornthwait climate classisfications. Details of Croatia’s climate could be found in Klimatski atlas Hrvatske / Climate atlas of Croatia 1961-1990., 1971-2000.

Continental climate

Continental Croatia has a temperate continental climate and throughout the whole year it is in a circulation zone of mid-latitudes, where the atmospheric conditions are very variable. They are characterised by a diversity of weather situations with frequent and intense exchanges during the year. These are caused by moving systems of low or high air pressure, often resembling vortices hundreds and thousands of kilometres in diameter. The climate of continental Croatia is modified by the maritime influence of the Mediterranean, which is stronger in the area south of the Sava River than in the north, and which weakens towards the east. The next local climate modifier is orography which, for example, facilitates the intensification of short-term heavy precipitation on the windward side of the orographic obstacle or the appearance of precipitation shadow on the leeward side. Weather characteristics differ between seasons.

During the cold part of the year, stationary anticyclonic weather types, with foggy weather or low clouds and a very gentle air flow, are prevalent. Such conditions are favourable for frost occurrence.

In spring, fast-moving cyclonic weather types (cyclone and trough) are characteristic, resulting in frequent and sudden weather changes, from rainy to dry periods, from calm to windy, from colder to warmer. In April, there are usually about ten successive days with a moderate, even strong cold northern wind at the front side of the meridional anticyclone stretching from Scandinavia to Central and even Southern Europe.

In summer, the zero pressure gradient fields and a cooling night breeze blowing down mountain slopes are interrupted by cold fronts passing through. They bring in fresh air from the Atlantic, with very strong air mixing, increased wind, thunder and showers from dense clouds with vertical development. This unstable atmosphere stratification and convective clouds usually stay for a day or two after the cold air outbreak, until the new air mass is warmed by the land surface.

In autumn, periods of calm anticyclonic weather are very common, but there are also rainy days as cyclones pass over Croatian territory. Calm weather in early autumn is characterised by warm and sunny days and fresh nights with heavy dew and low fog patches over streams and rivers, which dissipate quickly by the morning. In late autumn, calm weather is cold, foggy and gloomy; in open plains there is a short period of sunshine through fog around noon. On mountain peaks, however, the weather is sunny throughout the whole day.