As spring turns to summer, millions of people around the world are bracing for an annual nuisance: mosquitoes. But this year, experts warn that the buzzing menace could be worse than ever, largely due to changing climate conditions.

Long, warm seasons are providing ideal breeding grounds for these insects. Mosquitoes thrive in humid weather and stagnant water, which has become more common with intense rainfall and rising global temperatures.

The issue goes beyond just itchy bites. Mosquitoes are notorious carriers of deadly diseases, including malaria, dengue fever, the Zika virus, and West Nile virus. Public health officials are increasingly concerned that as mosquito populations expand into new geographical areas, the risk of these diseases spreading to new populations is also increasing.

“We are seeing seasons extending further into the year and mosquitoes appearing in regions where they were previously uncommon,” said Dr. Anya Sharma, an entomologist studying vector-borne diseases. “The combination of more insects and a longer period of activity is a significant public health challenge.”

Authorities advise homeowners to eliminate standing water around their properties—such as in flower pots, bird baths, and gutters—to reduce local mosquito populations.