Image from MetService.
The MetService said weather radar overnight appeared to show a lot of light precipitation over the northern half of the North Island and west of Auckland.
However, they know there was almost no rain in the area at the time.
We're not completely sure, but we strongly suspect the echo is a swarm of insects," the weather agency said.
"To show up in radar imagery like this they must be about as large as, and as numerous as, precipitation particles."
