Split and Hvar's mosquitoes work two shifts. Two coats of repellent cover both.

Yes, by day and after dark. The Asian tiger mosquito, the dominant species on Croatia's coast, bites in Split's palace courtyards, on café terraces and in Hvar's gardens in the morning and late afternoon, and house mosquitoes and sand flies take the night. Disease risk is low. Split-Dalmatia county has never recorded local dengue or chikungunya, and its single West Nile case on record came in 2025.

The day shift and the night shift

In a survey of 126 Adriatic sites in August and September 2011, the tiger mosquito made up 81.4% of the 3,699 mosquitoes collected. In Split it laid eggs from April to early December in 2009 and 2010, with the highest numbers from June to early September. It is small and striped, breeds in tiny pockets of standing water and bites by day, mostly in the morning and late afternoon, so the stone lanes and courtyards inside Diocletian's Palace, the terraces behind the Riva and Hvar's gardens all tend to bring bites. On the open seafront of the Riva itself, a sea breeze tends to help.

After dark, Culex house mosquitoes come through open shutters in old-town apartments, and sand flies, tiny and silent, bite from dusk to dawn. Reports from Hvar town and Split are mixed.

The routine is two coats. Put repellent on in the morning or before a late-afternoon walk, and again before dinner on the Riva or Hvar's harbor, which covers sand flies too. In apartments without screens or air conditioning, close the shutters at dusk or run a plug-in vaporizer. Bites pick up after rain, and July and August evenings bring the most. Our repellent timing guide shows how long one coat lasts.

What the county's record shows

No locally acquired dengue has been recorded in Split-Dalmatia. Croatia's only outbreak on the European Centre for Disease Prevention and Control (ECDC) list was 10 cases on Korčula and the Pelješac peninsula in 2010, down the coast in Dubrovnik-Neretva county, and ECDC has recorded no local dengue or chikungunya in Croatia in 2025 or 2026 through October 21. West Nile, spread by Culex at night, reached the county for the first time in 2025, with a single human case. ECDC's tables show none there in 2026, when all 18 of Croatia's cases were inland, around Zagreb and in the north and east.

Sand flies are the biter with a local history. They spread leishmaniasis, which CDC lists for Croatia, and central Dalmatia was long a focus, with hundreds of cases recorded from the 1930s to the 1950s, many around Split and Makarska. Human cases have been sporadic since the 1960s. The evidence that the parasite still circulates comes from older studies. In 2003, 14.7% of dogs tested in the city of Split were seropositive, and a 2007–2009 survey found antibodies in 22.2% of residents of central coastal Dalmatia. Sand flies also carry Toscana virus, and a 2012 study found antibodies in 53.9% of island residents, though illness is only sporadic. Evening repellent covers sand flies.

CDC lists no malaria medicine for Croatia, and the yellow fever vaccine is neither recommended nor required. After hikes in the hills of Brač or Hvar, check for ticks. CDC recommends the tick-borne encephalitis vaccine for travelers with extensive tick exposure.

Where you're going

How the main stops compare for a June–September trip.

The Croatia briefing covers Zagreb and the rest of the country, and our Dubrovnik briefing covers the coast farther south, including Korčula.

What travelers report

Paraphrased from TripAdvisor forum threads and linked so you can read them in full. None is dated, and bites on this coast vary a lot with the weather and where you stay.

• Hvar · June

  One poster said mosquitoes attack after about 4 pm; a later June visitor saw none, noticed only a few people with bites and felt repellent was unnecessary. TripAdvisor ↗

• Split · May

  In a Split mosquito thread, a May visitor to the Split area reported no problems, while posters still advised carrying repellent. TripAdvisor ↗

• Split and Dalmatia · September

  Asked whether mosquitoes are bad in September, replies said they are common but vary from place to place and come out mostly in the evening and at night. TripAdvisor ↗

One rule outlasts the trip. A fever during the trip or within two weeks of returning means a doctor visit, and you tell the doctor you were in Dalmatia, where leishmaniasis and sand fly viruses occur.

Traveler questions