A loud bang, described as a "sonic boom", jolted Tauranga residents awake around 3am on Sunday.
Residents from Brookfield to Te Puna reported being woken by a single loud bang which rattled windows and upset pets.
Police received several calls about the loud bang.
A MetService meteorologist said it was likely a thunderstorm just over Tauranga Harbour was the culprit.
Brookfield resident Roderick Davison said he was fast asleep when a loud bang, which "sounded like a sonic boom", woke him up around 3am.