It sounds like something out of a cartoon, but "animal rain" — flightless creatures like fish and frogs falling to the ground along with rain — is a real phenomenon repeatedly observed worldwide. Here's the cause and mechanism behind it.
Animal rain isn't superstition or urban legend — it's a real weather phenomenon repeatedly observed and reported in multiple countries. Cases of fish falling from the sky have made news in Australia, and cases of frogs falling have been reported in other regions.
The most likely cause is a waterspout forming over water. When wind direction near the surface differs from wind aloft, a vortex forms, and as warm, moist surface air rises to build a cumulonimbus cloud, the vortex gets drawn up into the cloud, forming a large waterspout. Its powerful updraft can pull small fish, frogs, and similar animals up along with the water near a lake or ocean surface.
A waterspout's updraft connects to the surrounding cumulonimbus cloud. So small animals lifted up along with water travel with the cloud on the wind, and when moisture in the cloud turns to rain, the animals fall to the ground with it. That's why it can look like fish or frogs suddenly appear falling somewhere quite far from where the waterspout actually formed.
Small, lightweight animals abundant near where a waterspout forms are more easily swept up by the updraft. So one case might show only fish falling, another only frogs — this simply reflects the local ecology of the water body at the point of origin, not anything supernatural.
Waterspouts tend to form in coastal or lake areas in summer, when the atmosphere is unstable and cumulonimbus clouds develop easily. Saving the places you check often in sanCheck helps you check advisories issued during unstable atmospheric conditions ahead of time.