Strange cloud formation puzzles Bay Area 🤔☁️ https://t.co/XcNjpYkvuF pic.twitter.com/3AKO3yqYvw — KRON4 News (@kron4news) September 14, 2018

Some around the Bay Area were scratching their heads over a strange cloud formation seen mostly in San Bruno, San Mateo and Burlingame. The clouds took the form of a giant wispy hole in the sky.

The formation is something known as a “fallstreak hole,” or “hole punch cloud,” according to the National Weather Service in a KRON report.

The holes are formed when the water temperature in the clouds is below freezing, but the water has not frozen. When ice crystals do form, water droplets around the crystals evaporate and leave a circular hole in the cloud.

I know I’ve said this a lot lately but look up now. A rare phenomenon, #fallstreak hole or #punchcloud, occurring in several parts of this cloud deck over the bay area. pic.twitter.com/MGYChSlyKe — Mike Nicco (@MikeNiccoABC7) September 14, 2018

Rest assured, the sky is not falling after all.