Earlier this month, weather radar over La Crosse, Wisconsin picked up what looked like a moderate shower. Turns out, it was a massive swarm of mayflies. Check out the swarm from July 20 below.
The occurrence isn’t a rare one for La Crosse residents. Dan Baumgardt with the National Weather Service in La Crosse, Wisconsin told the AP, “Almost every night in the summer, there’s some sense on the radar that there’s something coming off the river.”