Can mosquitoes fly when it rains?

Mosquitoes shouldn’t be able to fly in the rain, but they still do!

Despite being roughly the same size, a single raindrop can weigh up to 50 times more than an average mosquito. So, a mosquito flying in the rain is like a person wandering about when it’s raining buses! Common sense says mosquitoes shouldn’t survive the rain, but they are a stubborn bunch.

So how do they survive the rain?

Well firstly, they do not get wet. The glassy wings and the tiny hairs on their bodies are designed to repel water. So, when a raindrop bounces off of a mosquito, one of the two scenarios may occur:

1. Raindrop hits wings or legs [very probable]
2. Raindrop hits the core body or head [unlikely]

In the first scenario, the mosquito rotates around the raindrop due to its hydrophobic body and regains normal flight with minimal effort. In other terms, the mosquitoes just shake it off.

In the second scenario, the mosquito gets hit hard and drops in altitude. But it still manages to survive by taking on only a fraction of the full momentum [2–17% depending on the mosquito] of the raindrop upon impact. It does this by making the collision inelastic. The secret to this is to go with the flow.

Besides, the drastic difference in mass between the mosquito and the raindrop actually becomes an advantage when we analyse the system by applying the law of conservation of momentum.

And that is how the pesky little mosquitoes fly in the rain.

If you’re interested in a detailed analysis, you should take a look at this research paper by Dickerson et al. published in the Proceedings of the National Academy of Sciences. The pictures in my answer were all borrowed from it. They even have beautiful slo mo footage of water drops hitting mosquitoes.