Crete bites more than most Greek islands. Heraklion is where West Nile turned up.

Yes, more than on most Greek islands. Crete's farm plains, gorges and gardens keep mosquitoes busy from June to September, and the tiger mosquito adds daytime bites to the evening shift. West Nile is the health item. The island had 6 locally acquired cases in 2026, 5 of them in the Heraklion area, during Greece's worst season on record.

West Nile around Heraklion

The European Centre for Disease Prevention and Control (ECDC) lists 5 locally acquired cases in 2026, through October 21, in Irakleio, the Heraklion regional unit, 3 of them confirmed and 2 probable, with the first falling ill on August 18. Rethymni, the Rethymno unit, had 1 confirmed case with onset on August 17. Chania and Lasithi had none. Irakleio's first-ever human case came in 2025, with onset on September 8. The virus isn't new to the island. A 2022 study of Crete's mosquito surveillance notes 3 cases in Rethymno in 2017–2018, and horses in Chania, Heraklion and Lasithi developed antibodies in 2017.

For scale, Greece counted 457 cases by October 21, and Attica alone had 218 by October 7. West Nile is spread by the house mosquito, Culex pipiens, which bites from dusk into the night. Put repellent on ankles, arms and neck before every outdoor evening meal from June to September, and treat it as routine in Heraklion, Hersonissos and Malia in August and September, when the island's cases have started. There is no West Nile vaccine, and travelers over 65 face the highest risk of severe illness.

Why the west bites more

In mosquito surveillance at tourist and residential sites across Crete in 2018–2020, the house mosquito made up more than 85% of catches, and 84.9% of all mosquitoes were caught in the wetter west, in Chania and Rethymno. Heraklion and Lasithi had far fewer.

The tiger mosquito works the day shift. First found near Chania in 2014, it is now established on Crete, according to the April 2026 ECDC/EFSA map, and it bites in gardens, courtyards and shady hotel grounds, with peaks in the morning and late afternoon. A 2017–2018 study in Chania found its numbers peaked in August, so reapply repellent on garden and shade days. Greece has had no local dengue or chikungunya, which this mosquito can spread, and ECDC reported none in 2026.

Sand flies bite from dusk to dawn. CDC's Greece page lists leishmaniasis, and Crete is one of the Greek regions where it is most common, though it is rare in travelers. The same evening repellent covers them. At night, close the windows at dusk or run a plug-in vaporizer; an air-conditioned room helps. CDC also lists two tick-borne diseases for Greece, so check for ticks after a gorge hike.

Where you're staying

How the main areas compare for a June–September trip. Crete's mosquitoes stay busy into the fall, and in 2018 Heraklion's numbers peaked in late September and Chania's again in early October. Crete's West Nile cases in 2025 and 2026 began between mid-August and early September.

Island-hopping north? Our Santorini & Mykonos briefing covers the drier, windier Cyclades, and the Greece briefing covers Athens and the mainland.

What travelers report

Paraphrased from TripAdvisor forum threads and linked so you can read them in full. Neither is dated, and bites on Crete vary with the region, the garden around you and the wind.

• Santorini, Crete and Athens · late June

  Asked whether mosquitoes would be bad in the last two weeks of June, a poster who had visited all three places in late June reported no mosquito problems anywhere; another said Santorini caused no trouble, that Athens sometimes has some, and recommended a pharmacy repellent lotion. TripAdvisor ↗

• Crete · late June

  In a thread asking about end-of-June mosquitoes, a poster who had visited Crete in May, June, July, September and October said no one month was worse than another; another said that if mosquitoes are bad at the start of the season they stay bad all season, and that a mild winter may affect numbers. 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 on Crete.

Traveler questions