Iceland's first mosquitoes turned up in 2025. Lake Mývatn's flies are the ones you'll meet.
Three mosquitoes found on a farm north of Reykjavík made the news, and no one knows yet whether they stayed. For a summer trip, the insects that matter are the midge swarms and biting black flies at Lake Mývatn in June and July.
Barely. Iceland had no mosquitoes on record in the wild until October 2025, when three were found on a farm in Kjós, north of Reykjavík, and no one knows yet whether they survived the winter. CDC lists no insect-borne diseases for Iceland. The insects you'll actually meet in summer are at Lake Mývatn in the northeast, where midges swarm in huge numbers and black flies from the Laxá river bite.
The 2025 mosquito find
Iceland was long one of the few places with no mosquitoes. In October 2025 the Natural Science Institute of Iceland confirmed three Culiseta annulata mosquitoes caught by an amateur insect watcher in Kjós, the first recorded in the wild there. An institute entomologist said they probably arrived by ship or container, and the species tolerates cold. It is not one of the species linked to dengue or chikungunya. No follow-up in 2026 has shown whether a population took hold. For a summer trip around Reykjavík, the Golden Circle and the South Coast, biting insects are close to a non-issue.
Lake Mývatn in June and July
Mývatn means "midge lake," and in early and mid summer it earns the name. On calm days the midges rise in dense clouds that are hard to escape without a head net. Most of them don't bite, so the swarm is miserable more than painful, and repellent has a reputation for doing little against clouds that thick. A fine-mesh head net works. Local service stations sell them, and it pays to have one in the car before you reach the lake. The swarms have grown with warmer summers, the Reykjavík Grapevine reported in 2016.
The biter is a black fly, Simulium vittatum. A 1972 Icelandic agricultural research paper found it breeds in running water such as the Laxá river rather than in the lake itself, and feeds on the blood of people and animals. Like black flies elsewhere, it bites by day near running water, and it tends to be worst on calm, warm days in June and July. Picaridin or DEET on exposed skin and long sleeves handle it, and the head net covers your face. Our picaridin vs. DEET comparison explains the choice.
Wind is the free defense against both, so save lakeside walks for breezy spells. By August the swarms thin out, and by September or October they're gone. This is a different insect problem from Scotland's, where the Highland midge bites hard; our Scotland midge briefing covers that one.
Where you're going
How the two halves of a typical summer trip compare.
Lake Mývatn & the Laxá river
Dense midge swarms on calm days in June and July, mostly non-biting but hard to escape without a head net. The black flies from the Laxá do bite, so add repellent and long sleeves.
Reykjavík, the Golden Circle & the South Coast
Hardly any biting insects, and no repellent needed on a typical summer itinerary. The 2025 mosquito find was at a farm in Kjós, north of Reykjavík, with no sign yet of a population.
The Iceland kit
- A fine-mesh head net: the one item that works against the swarms. Pack one from home or buy one at a local service station.
- Picaridin 20% travel sprays for the black flies by the Laxá. The 3.4 oz size rides in a carry-on.
- A light long-sleeved layer, which Icelandic summer weather calls for anyway.
What travelers report
Paraphrased from a forum thread and linked so you can read it in full. It isn't dated to this season, and conditions at the lake change from one calm or breezy day to the next.
- Iceland (Mývatn, south) · late August
In an older, closed thread, a traveler asked about black flies in the south in late August. Replies said midges are the main nuisance, around Mývatn and near horses, most common in early and mid summer and much fewer by August; that they can bite but are not dangerous; that a cheap head net from a service station is the best defense; and that Iceland has no mosquitoes. TripAdvisor ↗
As on any trip, a fever during or after it means a doctor visit, and you tell them where you were.
Traveler questions
Are there mosquitoes in Iceland?
Almost none. The first recorded in the wild were three Culiseta annulata mosquitoes caught on a farm in Kjós, north of Reykjavík, and confirmed by the Natural Science Institute of Iceland in October 2025. They probably arrived by ship or container, and it isn't known whether they established. The species is not linked to dengue or chikungunya. You're unlikely to need mosquito repellent for Reykjavík, the Golden Circle or the South Coast.
Do the Mývatn midges bite?
Most of them don't. The midges that swarm over Lake Mývatn are mostly non-biting, so they are a nuisance more than a source of bites. The biter is a black fly that breeds in the Laxá river and feeds on the blood of people and animals. A fine-mesh head net handles the swarm, and picaridin or DEET on exposed skin plus long sleeves handle the black flies.
When can I visit Mývatn without the midges?
The swarms and black flies peak in June and July, thin out by August and are gone by September or October. On any summer day, wind keeps them down, so a breezy day at the lake beats a calm one.
Do I need any vaccines or medicines for insects in Iceland?
No. CDC's Iceland page lists no insect-borne diseases, recommends no malaria medicine and does not recommend or require the yellow fever vaccine.
Sources
Health authorities, surveillance reports and news coverage of official bulletins used for this briefing, last checked October 2026. Traveler reports are linked where they appear. This page summarizes public-health guidance and is not medical advice.