You’re not imagining it, there are more mosquitoes in the UK this year

Hotter summers caused by climate change are leading to an increase in the number of mosquitoes in the UK. Rising temperatures in the northern hemisphere are forcing populations of the insect further north, meaning Britain is now in the upper end of the “thermal limit” for certain species typically found in hotter countries, experts have said. While warmer summers are leading to a rise in all species of mosquito in the UK, one in particular, Aedes aegypti, was found to be breeding in Britain for the first time this year. Shorts Aedes aegypti carries the dengue, Zika and chikungunya viruses, although the UK Health Security Agency says the risk to the British population from these diseases is very low. This species of mosquito is not currently common in the UK, but individual insects have been discovered here four times in recent years. Larvae of Aedes aegypti were discovered in residential properties in east London for the first time over the summer. Cuts to aid funding increasing risk to humans Experts have warned that cuts by the UK and US governments to aid funding – which also pays for vaccination and public health programmes in developing countries where mosquito vector viruses are native – are increasing the risk to human populations. An abundance of other species – which do not carry deadly viruses – are also appearing more often in Britain due to hotter summers. This appears to be linked to a rise in people seeking medical treatment for mosquito and other insect bites. Figures published by NHS England show an increase of visits to their website page on bites and stings of 35.2 per cent between May and July, from 90,206 to 121,976, as the country experienced multiple heatwaves. And hospital visits for insect and spider bites more than doubled in May – the month of the first heatwave – compared with previous months. Official figures have revealed that summer 2026 was the UK’s hottest on record and the joint hottest globally. More people seek medical treatment for bites The National Pharmacy Association (NPA) said its members had reported an increase in patients seeking medication for infected mosquito bites this summer. Henry Gregg, chief executive of the NPA, said: “With the record-breaking heat we have been experiencing over the summer, more people have understandably been spending time outside and therefore pharmacies have been reporting an increase in patients presenting to them with infected mosquito bites. “Although most insect bites do not require treatment and will heal on their own, there is a risk in some circumstances that they can become infected.” While some species of mosquito are endemic in the UK, climate change could lead to Aedes aegypti becoming established in the country within the next few decades. The National Pharmacy Association said its members had reported an increase in patients seeking medication for infected mosquito bites (Photo: Getty) Mosquitoes’ ‘home range’ is moving northwards Dr Lauren Cator, associate professor in vector and transmission ecology at Imperial College London, said the “home range” for these mosquitoes is expanding further north and getting closer to the UK. She told The i Paper: “The probability of the mosquito finding its way into our environment has changed. In terms of climate change, what very much has changed is what we would call the home range or the area where this mosquito is able to breed year-round and reach high enough numbers that it’s able to establish. “And that distribution has crept all the way up through the Mediterranean Basin and now up into Europe, and so its home range is much closer to us now. So it has not as far to go to get into the UK. “Certainly when it’s warm in general, and I think I can say that confidently because we’re at the lower end of the thermal limit of these mosquitoes, the warmer it is, the higher the abundance tends to be in general.” Cuts to UK aid funding, first by the previous Conservative government from 0.7 per cent of GDP to 0.5 per cent, and then to 0.3 per cent by Sir Keir Starmer’s administration, risks hampering global tracking of mosquitoes that carry deadly viruses, Cator added. She said: “Those funding cuts do greatly impact our ability to track, understand and predict these populations and the accompanying risk. “A really key point is that these insects really don’t care about borders, and so we do need international collaboration to inform and co-ordinate our responses.” ‘We need to remain vigilant’ Professor Aubrey Cunnington, head of the department of infectious disease and professor of paediatric infectious disease at Imperial College London, said the disease-carrying mosquito Aedes aegypti was not going to cause a significant level of harm in the UK in the short term. But he added: “In the longer term, I think it reflects that we are likely to see changes in vector species in the UK, and eventually that may lead to diseases in the UK which we haven’t seen here being transmitted in the UK previously. “There’s a prevailing view in the scientific community that we are seeing changes in the distribution of vector species that are occurring with climate change. “The range that they’re able to live in is expanding. It’s getting warmer in the UK – mosquitoes generally like warmer environments, so it’s likely that that is one of the key factors favouring this. “I think we need to remain vigilant for that now. We may start to see transmitted cases of infectious diseases in the UK that haven’t previously been transmissible in the UK because we haven’t had the vector species here.” Cunnington said it was “very unlikely” that Aedes aegypti mosquitoes in the UK would feed on someone who has the dengue virus and then transmit it to someone else, because most people in the UK do not carry the virus. This infection is spread through a bite of the Aedes aegypti mosquito and causes high fever and intense body aches in symptomatic cases. He added: “The big picture message is that if we’re not controlling the diseases in the countries where there is the greatest burden, then there is more risk of those diseases entering other countries associated with travel, trade, immigration, whatever means. “But controlling them in the places where they are most prevalent is probably the best way. It’s a good way to protect ourselves and the UK from those diseases as well.”