For the first time in recorded history, mosquitoes have been found living in the wild in Iceland, a country long celebrated for its mosquito-free status. This remarkable discovery, confirmed in October 2025, is being closely linked to the effects of climate change, with Iceland now warming at a rate that far outpaces much of the Northern Hemisphere. The event has not only sparked scientific intrigue but also raised questions about how global warming is quietly transforming even the most unlikely corners of our planet.
The story began in the glacial valley of Kjós, about 20 miles west of Reykjavík. It was here that Björn Hjaltason, an avid insect enthusiast, noticed something unusual in his garden. As dusk settled on October 16th, Hjaltason spotted what he described as a "strange fly" perched on a red wine lure—a ribbon used to attract moths. "I could tell right away that this was something I had never seen before," Hjaltason told the Icelandic newspaper Morgunblaðið. Acting quickly, he captured the insect, which turned out to be a female mosquito. Over the next short while, he trapped two more—another female and a male—and handed them over to local authorities for testing.
Laboratory analysis at the Icelandic Institute of Natural History confirmed the identity of the mosquitoes as Culiseta annulata, a species well known for its resilience to cold and widespread presence across northern Europe and parts of North Africa. According to entomologist Matthías Alfreðsson, the specimens were all collected from red wine ropes, a technique typically reserved for moth collection. The finding marked the first verified case of mosquitoes surviving naturally outdoors in Iceland, a nation whose harsh winters and brief summers have historically kept such insects at bay.
Until this discovery, Iceland was one of only two places on Earth—alongside Antarctica—without any known mosquito population. The cold climate and a scarcity of stagnant water, which mosquitoes need for breeding, had made the island inhospitable for these insects. But that appears to be changing. As reported by BBC, rising temperatures, longer summers, and milder winters—hallmarks of a warming climate—are creating more favorable conditions for mosquitoes to survive and possibly thrive in Iceland.
Climate data supports this shift. According to World Weather Attribution, Iceland is now warming up to four times faster than the rest of the Northern Hemisphere. In 2025, the country shattered several temperature records, including a 10-day stretch in May where temperatures exceeded 20 degrees Celsius—an unusual event for a nation accustomed to brief, chilly summers. The record high for May was set at 26.6 degrees Celsius at Egilsstaðir Airport, as noted by BBC. These warmer and more humid conditions are ideal for mosquito activity, which peaks when humidity is at least 42% and temperatures range between 10 and 35 degrees Celsius, according to a 2020 study by the U.S. National Institutes of Health.
So, how did the mosquitoes get to Iceland in the first place? While the exact route remains unconfirmed, scientists suggest the insects most likely arrived via international freight or on ships and containers. Mosquitoes have occasionally been detected on aircraft landing in Iceland, but until now, none had survived long enough to establish themselves outdoors. The adaptability of Culiseta annulata—which can lay eggs in artificial containers such as buckets, barrels, and flowerpots—makes it a particularly successful invader, even in regions with short summers.
Despite the dramatic headlines, the species discovered in Iceland is not currently considered a threat to public health. As the Icelandic Institute of Natural History and the U.S. National Institutes of Health both point out, Culiseta annulata is a biting nuisance but does not carry common mosquito-borne diseases in colder regions. "A biting nuisance, rather than a deadly foe," a 2017 study described the species. Globally, however, mosquitoes remain the world’s deadliest animals, with more than 3,000 species responsible for transmitting diseases like malaria, dengue fever, and West Nile virus. The American Mosquito Control Association estimates that over one million people die each year from mosquito-borne illnesses.
The arrival of mosquitoes in Iceland is more than a quirky news item—it’s a potent symbol of the broader ecological changes underway due to climate change. As Greek Reporter and Colombia One both highlight, the presence of new insect species in Iceland is part of a wider trend seen in recent years, driven by both global warming and increased international transport. "This is another great example of the value of citizen scientists in detecting invasions of disease-spreading mosquito species in new areas," said Ryan Carney, a biologist at the University of South Florida, emphasizing the crucial role of everyday people in reporting ecological shifts.
The science behind this shift is clear: mosquitoes are cold-blooded creatures, meaning their body temperature—and thus their activity levels—are dictated by the environment. As global temperatures rise, mosquitoes are able to invade and survive in habitats that were once too hostile. Warmer climates also extend the mosquito breeding season and boost their reproductive capacity, leading to more frequent biting and, in some regions, increased disease transmission. Research published in PLOS and summarized by Stanford Earth Matters magazine shows that while higher temperatures can sometimes limit mosquito activity in already hot places, they dramatically increase the risk of mosquito-borne diseases in areas that were previously too cold, like Iceland.
Yet, not all scientists are convinced that climate alone explains the sudden appearance of mosquitoes in Iceland. Mr. Alfreðsson of the Natural Science Institute of Iceland cautioned that their presence could "indicate a recent introduction to the country, possibly via ships or containers," and that further monitoring will be needed to see if the insects can establish a permanent population. Still, the consensus is that climate change is making Iceland—and other northern regions—more welcoming to species that once would have perished in the cold.
With the arrival of Culiseta annulata in Iceland, Antarctica now stands as the last continent without mosquitoes. As scientists continue to monitor the situation, the discovery serves as a vivid reminder: even the most isolated and seemingly immune environments are feeling the effects of a warming world. For Icelanders, the presence of mosquitoes is a new reality—one that underscores the far-reaching and sometimes unexpected consequences of climate change.
