Croatia Geography, Climate & Nature

Croatia bends in a crescent from the Danube in the north-east to the Bay of Kotor's border in the far south, and its shape is the key to its geography. The coast faces south-west onto the Adriatic across more than a thousand islands and islets, 48 of them permanently inhabited, and two of them -- Cres and Krk -- the largest in the sea. Behind the coast the Dinaric Alps run the length of the country, rising to Dinara at 1,831 metres; behind them the land falls to the Pannonian plain, where the Sava, Drava, Mur and Kupa drain to the Danube.

Half the country is karst: limestone that swallows rain and returns it as springs, sinkholes and rivers that vanish and reappear. It is why the coast is dry and the islands short of water, why the interior has the lakes of Plitvice and the canyon of the Krka, and why so much of the mountain country is cave. The Dalmatian coast is the karst meeting the sea, its islands the drowned ridges of the same rock.

The mountains also make the weather. The bora is a cold north-easterly that pours down from the interior plateau when high pressure sits over its snow; near Senj, Karlobag and the southern mouth of the Sveti Rok tunnel it can reach 220 km/h, it starts suddenly on a clear day, and it closes roads. A trip that crosses the mountains to the coast, or drives the coast road under Velebit, should be planned with it in mind.

The coast and islands have a Mediterranean climate of hot, dry summers and mild, wet winters; the mountains behind them have real winters with snow; and Zagreb and the eastern plain are continental, cold in January and hot in July. The three run in bands from south-west to north-east, so a two-hour drive from the sea can cross all of them.

The wind is the thing to know. The bora blows hardest when polar high pressure sits over the snow-covered interior and a calm low lies over the warmer Adriatic; it comes down the mountain passes suddenly, on a clear and calm day, and near Senj, Karlobag and the Sveti Rok tunnel it has reached 220 km/h. It is strongest in winter and can arrive in any month; the roads authority bans some vehicles from the Velebit roads and the D8 coast road when it blows, and sailors keep to harbour. Its opposite, the humid southerly jugo, brings the rain.

Best Destinations by Month has the practical reading: coast from May to September with June and September the sweet spot, interior and mountains in spring and autumn, Zagreb in winter.

Croatia hosts around 37,000 known plant and animal species, and the true number is thought to lie between 50,000 and 100,000. More than a thousand are endemic -- found nowhere else -- and they concentrate where the geography isolates: the Velebit and Biokovo mountains, the Adriatic islands, and the karst rivers whose underground courses have bred their own cave fauna. The law protects 1,131 species.

The country's answer to that inheritance is a dense network of protected land for its size: eight national parks, two strict reserves and thirteen nature parks. Plitvice, founded in 1949, is the oldest and a World Heritage Site; Velebit Nature Park is a UNESCO biosphere reserve; the Kornati, 89 islands and the sea between them, have been a national park since 1980.

No species-level survey was consulted for this page beyond the sources named in the data file; the figures are indicative.

The birds are the easiest wildlife to meet. Cres carries a relatively large breeding population of the endangered Eurasian griffon vulture, which soars over the island's cliffs, and forms part of the Kvarner Islands Important Bird Area; the vultures are why the island's northern villages keep visitors off the cliff bases in the nesting season.

The karst rivers and lakes hold the rest of what a visitor will notice: the fish visible in the Plitvice lakes through water clear enough to see the bottom, and the endemic invertebrates of the caves and springs that make the Dinaric karst one of Europe's richest underground habitats. The Kornati's protected sea, 89 islands with almost nothing built on them, is the place to see what the Adriatic looks like without a harbour in it.

The forests of the Dinaric interior are large-carnivore country, but this page says only what its sources say, and they are silent on numbers; ask the park offices at Plitvice and Velebit, which are the people who know.