Here's Why Mosquito Season Keeps Starting Earlier And Earlier

If you've been feeling like mosquitoes are swarming around you earlier and earlier every year, you're not just imagining it. Consistent rises in temperatures globally and changes in precipitation patterns are the main reasons mosquito season begins earlier and lasts longer. These pests are highly sensitive to environmental conditions. The warmer winters are, the more mosquito eggs survive into spring, and the earlier rise in temperatures helps mosquito larvae mature much faster. A study by Climate Central found that mosquitoes thrive on days when the temperature is between 50 and 95 degrees Fahrenheit and the average relative humidity is 42% or above. These types of days are also defined as "mosquito days." 

In many states, these pests are appearing weeks ahead of the previous year. For example, the most recent vector-borne surveillance report (pdf) in June 2025 from New Jersey's health department shows the mid-Atlantic state entered mosquito season two weeks earlier than last year, with species like Culex mosquitoes, which often carry West Nile Virus, detected as early as Mid-April. The report also shows a clear indication of more widespread mosquito activity than in previous years for early June.

The earlier mosquito season starts and the longer it lasts, the higher the risk for people to contract mosquito-borne illnesses, such as Zika and West Nile virus. As global warming and climate change continue to disrupt familiar seasonal patterns, mosquitoes will no longer be just an issue of the summer season.

Mosquitoes may be early due to climate change, but it doesn't mean you have to be caught off-guard. From mistakes to avoid attracting mosquitoes to your yard to some simple DIY traps and repellents to try in your home and garden, there are so many ways to enter the itchy season more prepared than ever. Some even say beginning preparation as early as winter may be the perfect solution to getting rid of mosquitoes on your property. Since these annoying pests are dormant during the winter months, early intervention — such as removing all standing water where they can lay eggs and cleaning up debris that they can find shelter in to hibernate — will give you a jump start to preventing larger populations from developing in the warmer seasons.

Everyone should also keep in mind the 4 Ds when spending extended periods outdoors: Defend by deliberately applying and reapplying EPA-approved repellents, dress appropriately and wear closed-toe shoes and light-colored long-sleeve clothing, drain any water collection you spot, and avoid or limit time outdoors during the peak mosquito activity hours of dusk and dawn.

While there may be no 100% foolproof method, being vigilant and implementing the 4 Ds can greatly reduce the risk of getting bitten. You may also want to actively reach out to your local health department for mosquito updates throughout the spring and summer months. Preparing for the itchy season doesn't have to be complex, but consistency is very much key. The earlier you get started on preparation, the better your chances are of keeping the skeeters away.