I lived in a suburb outside of Dallas for several years and every year in March and April we used to get these monster spiders
These spiders were only about 6-7 inches long, but they would jump towards movement, and had such a hard back that even a heavy boot couldn't squish them.
We once found an enormous nest of them just down the road in a guard shack that all of the neighbors agreed to burn down.
Probably raining down because at least there'd be a chance of escape.
They're saying they don't know what caused it but there's got to be an more intelligent explanation. It rained frogs somewhere once and they figured that out.