Yes, rain creates new standing water for breeding and raises the humidity that mosquitoes need to stay active, so populations typically surge within a week or two after significant rainfall.
If it feels like mosquito populations explode every time it rains for a few days, you’re not imagining it. That’s a real problem and it’s one of the frustrating parts of living through a wet New Hampshire summer.
Female mosquitoes lay their eggs in or near standing water. A single rainfall event can create dozens of new breeding sites across a typical property. And it’s often in places you don’t expect like clogged gutters, wheelbarrow beds, plant saucers, tire swings, and low spots in the yard where water pools. Even a bottle cap of water is enough for some species of mosquitoes to breed.
It doesn’t help that mosquito larvae develop fast. In warm weather, they can go from egg to flying adult in as little as seven to ten days. So a heavy rain in early July means noticeably more mosquitoes by mid-July. Back-to-back rain events can make this even worse because they cause breeding cycles to overlap. New ones start while others are in progress.
Rain also increases ambient humidity, which mosquitoes love. They tend to dry out fast in the sun, which is why they hide where it’s damp and shady. After a good rain, there are more hiding spots that fit the bill.
There’s not much you can do about the weather, but you can control what happens on your property afterward. Walking your yard after a rain can help you find standing water, which you can then dump out. If you want to learn more about how to do this, check out our video on the 7 T's of mosquito control.
If you’re a Southern New Hampshire homeowner and you see mosquito surges after every rainstorm, Mosquito Squad of Southern New Hampshire can help. This can be done through barrier treatments that happen on a recurring schedule. A trained technician targets the resting and harboring areas across your yard. That knocks down mosquitoes as they rest, and keeps them from producing the next generation.
