In Christchurch, there has been a reddish blanket across the city for the entire day.

The haze was so thick in some areas people were driving with their headlights on. The fire service has fielded calls from across the lower South Island from people worried there were blazes nearby.

The ominous burnt orange skies have been captured in some stunning images posted to social media.

"The sky is unusually dark and foreboding over Dunedin, NZ, this morning," one person tweeted.

"Holding Australia in our thoughts. Wish we could send you some South Island rain."