Alps. Terrain (and vegetation – see ‘Plants’ below) on the islands varies considerably, from relatively flat and low to knobbly hills and crags, long sinewy ridges and spectacular sea cliffs, together with an endless succession of secluded coves, many of them accessible only by boat.
The hills on these islands are not particularly high – the greatest elevation on any of the islands is Vidova gora (780m), on the island of Brač; other prominent ‘island highs’ include Sv Nikola (628m, on Hvar), Osoršćica (589m, on Lošinj), Hum (587m, on Vis) and Obzova (568m, on Krk). While these figures may not seem very high, bear in mind that in most cases climbing them involves starting from just above sea level. In contrast, some of the islands are much lower – the highest point on Unije is only 95m above sea level.
Goli otok and Prvić, with storm clouds over Gorski kotar, from Kamenjak summit on Rab (Walk 5)
The Croatian coastline is spectacularly indented, with a total length of some 1777km over a distance of only around 526km (the latter figure measured as a straight line from the Slovenian to the Montenegrin border). This figure rises to 5835km when all the islands are included – the coastlines of the islands alone accounting for over 4000km of this figure. The coastline is rocky, with beaches made up of either rocks or, less frequently, pebbles. Fine shingle or true sandy beaches are rare, some of the best known – and consequently the most popular – being Zlatni rat (at Bol, on the island of Brač), Vela plaža (at Baška, on the island of Krk), Rajska plaža or ‘Paradise beach’ (at Lopar, on the island of Rab), Sv Duh (near Novalja, on Pag) and Saharun (on Dugi otok).
The islands are formed mainly of Cretaceous limestone – laid down on the seabed in the form of shells and other marine life when the Adriatic, along with the rest of this part of Central and Eastern Europe, was submerged beneath a shallow tropical sea some 66–145 million years ago. The Croatian Adriatic had become a coastal plain by the Pleistocene Era (2.5 million–11,700 years ago), with the gradual flooding of this coastal plain during the Holocene leading around 7000 years ago to the creation of the islands and the Adriatic Sea as we now know it.
The beginning of the trail from Kamenjak, with Goli otok ahead, on the island of Rab (Walk 6)
Croatia is karst country. Karst is formed by the gradual dissolving of the limestone rock by rainwater – or, more specifically, by the combination of rainwater and carbon dioxide from the earth’s atmosphere and the soil, which results in a weak solution of carbonic acid. Over millennia this process gradually enlarges surface drainage holes, as well as horizontal and vertical cracks and fissures in the rock, as the water percolates downwards, creating distinctive surface features such as vertical fluting (karren), solution pans, limestone pavement and sinkholes (doline), while beneath the surface it leads to the formation of an extensive network of caves and underground drainage channels, with all rainwater rapidly disappearing underground.
Collapses in the roof of these subterranean voids leads to the formation of larger sinkholes and cenotes. (Most of the deeper caves and sinkholes in Croatia are on the mainland, and some of these are extremely deep – Lukina jama on Velebit is among the 15 deepest sinkholes in the world.) Polje – large, level-floored depressions up to several kilometres in size, where a thin layer of alluvial soil has gradually accumulated – often form the only suitable areas for growing vegetables and the cultivation of crops.
Many of these features will be encountered while walking on the islands – for example Jama Komoračišće, a prominent sinkhole on Kom, Korčula (Walk 27), and limestone pavement on Šćah, Ugljan (Walk 15), to name but two. On the island of Rab a number of such karst and other geological features are highlighted on marked geological trails (Walk 7).
The island of Susak (and part of Unije) is unusual in being composed largely of sand and loess laid over a limestone base; while the quarries of Brač have long been famed for their white marble, much prized by sculptors and used to build Diocletian’s palace in Split during antiquity and, more recently, part of the White House in Washington DC.
Climate
The Croatian coast and islands experience a Mediterranean climate, and this is distinct and separate from the inland continental climate, which is significantly colder during the winter. The islands are protected from this colder climate by the mountain barrier of the coastal ranges (the Dinaric Alps).
Evening light on the east slopes of Sv Vid, seen from Pag town (Walks 13 and 14)
Summers on the coast and islands are hot and dry, with average mean temperatures of between 21°C and 22°C on the northern and central Dalmatian islands in June and September, and average mean temperatures of between 24°C and 25°C for the same area in July and August. At least half the days in July and August reach 30°C or above, although the highest temperatures recorded are not above 37°C–38°C. Even outside the summer months it is a balmy 18°C and 17°C in October and May respectively, and 14°C in April. Expect temperatures to be slightly higher in the south (Korčula, Dubrovnik) and very slightly cooler further north (Cres, Rijeka) – although these differences may be minimal. Hvar is supposed to have the most hours of sunshine on the Croatian Adriatic – around 2715 per year – with most other islands in central Dalmatia not far behind. Sea-water temperatures in central Dalmatia are usually around 22°C in June and September, and up above 24°C in July and August – most Croats would consider sea-water temperatures of anything less than 20°C decidedly chilly.
Whereas the heat can frequently become intense in early August on the mainland coast and in cities such as Split and Dubrovnik, summer temperatures on the islands are generally moderated by a light breeze, making them significantly more pleasant. These general observations do not hold true on islands with less vegetation, such as Pag or Goli otok (‘naked island’), where the heat during the summer months can be well and truly fierce.
Winters on the coast and islands are relatively mild, although frequently rainy (with less rain on the islands than the coast). January is the coldest month, with an average mean temperature of around 8.5°C on northern and central Dalmatian islands. November tends to be the wettest month. Snow is rare in the mainland coastal area (not so the mountains just inland from the coast, which see significant snowfall during the winter months) and rarer still on the islands – even Split and Dubrovnik are unlikely to see more than one day of snow, on average, in January.
Several winds can buffet the Croatian coast and islands at any time of year, the strongest (and most disruptive) of which is the bura – a cold northeasterly, which descends upon the Adriatic from the cols and high passes of Velebit in gusts which frequently reach gale force. The Venetian traveller Alberto Abbé Fortis, writing in the 18th century, even claimed that on occasions the bura would pick up young children and dash them against the walls of houses, and throw down horses loaded with salt. There is a saying in Croatia that the bura is born in Lika (the region behind the Velebit mountains), lives on Velebit and dies on the sea – but you can expect it to give the eastern coasts of Krk, Rab, Pag and some other islands a pretty good battering, too. When the bura really does blow, expect choppy (and cooler) seas, possible disruption to ferry and catamaran services, and possible closures of bridges to traffic (including buses) on the main coastal highway.
Trees bent by the bura wind, on the rocky northeast coast of Rab (Walk 6)
Other winds include the jugo, a moderate southerly (jug meaning ‘south’)
