Mosquitoes in Iceland

What was actually found, and how much it matters

On the evening of 16 October 2025, Björn Hjaltason checked a red-wine ribbon he had hung out to attract moths in his garden at Kiðafell in Kjós, about 30 km north of Reykjavík, and found something on it he did not recognise. He posted it to a Facebook group for Icelandic insects. Náttúrufræðistofnun Íslands, the Icelandic Institute of Natural History, confirmed the identification: three Culiseta annulata, two females and one male. The first mosquitoes ever recorded in the wild in Iceland.

Culiseta annulata is ordinary across Europe and the British Isles, and it is cold-tolerant — it overwinters as an adult in cellars, barns and outbuildings rather than dying back each year. The institute’s working assumption is that these arrived as freight. That is the entire event: three insects, one garden, one evening.

Three insects are not a population. Establishing whether Culiseta annulata can actually breed and overwinter in Iceland needs years of monitoring, and that monitoring did not exist before October 2025 because there was nothing to monitor. Anyone telling you Iceland now has mosquitoes — or that it definitely does not — is ahead of the evidence. What can be said is that for a trip in 2026, nobody is being bitten by mosquitoes in Iceland.

The reason the absence lasted so long is worth knowing, because it is not simply “too cold”. Greenland and northern Norway are colder in places and have mosquitoes in numbers that will drive you indoors. The explanation usually credited to Gísli Már Gíslason, professor emeritus of limnology at the University of Iceland, is about instability rather than cold: a mid-winter warm spell melts the ice on a pond and signals the pupae to start developing, and then the hard freeze comes back and kills them before they finish. What mosquitoes need is one thaw, in spring, that stays. Iceland has never reliably had one. Gíslason also, memorably, caught a mosquito in mid-air on a flight between Greenland and Iceland — so they had been arriving for years. They simply could not stay.

What actually bites you here — and what only annoys you

Iceland has no native snakes, no scorpions and no mosquito-borne disease. What it has is midges, and the distinction between the two kinds is the single most useful thing on this page. It also has ticks, which almost nobody mentions — that is further down, and it is the one item here worth taking seriously.

Rykmý Chironomidae — non-biting midge

These are the swarms. They emerge from the lake bed in colossal numbers in summer, they fly into your eyes, ears and mouth, and they have no interest in you whatsoever — they have no working mouthparts for biting. They are also the reason Mývatn has the largest concentration of breeding ducks in Europe: fifteen species feed on them. The lake is named after them. Mý is midge, vatn is lake.

Bitmý Simulium vittatum — blackfly

This is the one that bites. It breeds in running water rather than still, so it belongs to the river Laxá flowing out of Mývatn rather than to the lakeshore. Sources disagree about how readily it goes for people as opposed to horses and cattle, which is a genuine disagreement rather than a hedge — so treat it as an occasional nuisance near fast water in summer, not as something to plan around.

The one that nobody puts on the list: ticks

Iceland is routinely described as tick-free. It is not, and this is the correction on this page that actually matters for your health rather than your comfort. Ixodes ricinus — the sheep tick, the European carrier of Lyme disease — has been turning up in Iceland since at least 1976. A published surveillance study collected 26 questing ticks straight off vegetation at three sites in south and south-east Iceland, alongside 214 more from passive reporting, including ticks taken off dogs, cats and people that had been picked up locally rather than abroad. Four were found on migratory birds arriving in May, which is the likely route in.

The honest version, because the overstatement runs both ways. Researchers have not yet found questing larvae, which is the evidence needed to confirm a self-sustaining population, so the finding is “possibly established locally, in low abundance” — not a tick problem on the Scandinavian scale, and not a reason to change your plans. But if you walk through long grass or scrub in the south-east in summer, check yourself afterwards, the same as you would in Britain. That is a five-second habit and the rest of this page is about insects that merely annoy you.

Conditions at Mývatn right now

This is the weather. It is not a midge forecast. Nobody publishes one, and we are not going to invent one — the honest position is that midge numbers at Mývatn swing enormously between years, which is exactly why the lake has been under long-term ecological monitoring for decades. Read the temperature as what it is: warm and still is summer at the lake, and summer at the lake means midges. Readings from Open-Meteo at the coordinates our own records hold for each place, fetched 2026-10-16 10:02 UTC.

What to take, and what not to bother with

• A head net. The only thing that genuinely works. It costs a few pounds, folds into a pocket, and every shop around the lake sells them because everyone who lives there owns one. If you are going to Mývatn between roughly June and August, take one and you will simply never think about this again.
• Not repellent. Skin repellent is designed to stop something biting you. Non-biting midges are not trying to bite you — they are flying into your face because that is where they happen to be — so there is nothing for the repellent to discourage. It is close to useless here, whatever the packaging says.
• Sunglasses, genuinely. The specific misery of a chironomid swarm is insects in your eyes. Any glasses fix most of it.
• Keep the car windows shut at the lake. Obvious after the first time. Less obvious before it.
• Nothing at all, everywhere else. This is a Mývatn problem and, to a much lesser degree, a still-summer-evening-near-water problem. In Reykjavík, on the Ring Road, in the Westfjords — you will not think about insects once.