Iceland, one of the few places in the world to be free of mosquitoes, recorded its first sighting of the insect this month. Scientists have announced the discovery of three mosquitoes, two females and one male.The discovery was made by insect enthusiast Björn Hjaltason in his garden in the town of Kjós. “I could tell right away that this was something I had never seen before,” he told the Icelandic newspaper Morgunblaðið.While it is yet to be confirmed how mosquitoes arrived in Iceland, scientists have said that rising temperatures are making Iceland more hospitable to the insects.What is the link between global warming and the proliferation of mosquitoes?Mosquitoes, like all arthropods, are cold-blooded creatures and cannot regulate their body temperature in response to the surrounding environment. As a result, temperature is one of the biggest drivers of mosquito activity, and most of their species thrive in warmer weather.That is why global warming has enabled the insect to proliferate. Several studies have shown that with rising temperatures, mosquitoes can invade and thrive in habitats which once represented hostile environments.Also, scientists suggest that higher temperatures have extended the length of the season when mosquitoes are active, allowing a longer time period for the transmission of vector-borne diseases.Story continues below this adGlobal warming does not just help mosquitoes proliferate or survive for longer; it also impacts their reproductive capacity. A 2009 study, ‘Local and Global Effects of Climate on Dengue Transmission in Puerto Rico’, published in the journal PLOS, showed that an increase in temperatures stimulates egg hatching and accelerates growth of the larvae, thereby reducing the time for maturity. This, in turn, spikes the rate of transmission of diseases.In warmer climates, mosquitoes begin to bite more frequently. Only female mosquitoes are known to bite humans to get a “blood meal” — they extract proteins from our blood to produce their eggs. Higher temperatures result in a faster rate of blood meal digestion, making mosquitoes hungrier and leading to more bites. Note that male mosquitoes usually consume plant nectar, sweet plant secretions, and fruit juices.Elevated humidity plays a role in changing their behaviour, too. Research suggests that mosquito activity peaks on warm and humid days. The combination of humidity of 42% or higher and temperatures between 10-35 degrees Celsius is ideal, a 2020 study by the US National Institute of Health noted. High humidity is associated with increased feeding activity, survival, and egg development, another research, ‘Climate and Dengue Transmission: Evidence and Implications’, published in 2013, indicated.But mosquitoes are not susceptible to very warm and dry conditions. Their activity usually starts to slow down beyond 32 degrees Celsius, and so does the transmission of vector-borne diseases. For instance, malaria is most likely to spread at 25 degrees Celsius, while the risk of Zika is highest at 29 degrees Celsius, a 2019 report by Stanford Earth Matters magazine said. Anything beyond that, and mosquitoes are known to flounder.Story continues below this adAlso in Explained | How termite behaviour is linked to a warming world: Findings of a new study“The good news: higher global temperatures will decrease the chance of most vector-borne diseases spreading in places that are currently relatively warm. The bad news: warming will increase the chance that all diseases spread in places that are currently relatively cold,” it added.How is global warming impacting Iceland?Iceland is currently warming at four times the rate of the rest of the northern hemisphere. This has led to unprecedented glacier melt and frequent heatwaves.In 2025, the country broke several records for its high temperatures. Iceland rarely experiences highs of more than 20 degrees Celsius in May, and when it does, those heatwaves will last for around two to three days. However, that threshold was exceeded for 10 consecutive days this year in different parts of the country, according to a report by the BBC.Iceland also saw its hottest ever day in May, with temperatures reaching 26.6 degrees Celsius at Eglisstaðir Airport, the report said.