The red dust which hit vast areas of eastern Australia on Wednesday has travelled right across the Tasman.

The dust has been detected in Auckland, meaning it travelled 2,160 kilometres across the Tasman.

New Zealand Met service forecaster Chris Noble says most of the dust fell overnight.

"It's not very thick," he said. "The reports have been that people have seen it on their cars and their windscreens.

"Most of that dust has now been carried to the east of the country, as that front has moved away out into the Pacific Ocean.

"Most of the dust has fallen out of the sky and that's probably the last of it now."

Mr Noble says many New Zealanders reported this morning that the sunrise was more red than usual.