Record breaking temperatures and ongoing drought conditions have forced a rare fire ban across Otago.

The latest NIWA figures show temperatures across the South Island skyrocketed in 2015.

The lack of rain hasn't helped: Hanmer Springs had its driest year in nearly a century, Culverden had one of the driest on record, and Christchurch had the hottest temperature in December.

Weather Commentator Richard Green said the fire ban in the South is unusual.

"Otago is looking at a total fire ban with very dry conditions for Dunedin and the surrounds, for Central Otago, further south, eastern Southland around Gore, and even in Invercargill. We don't often say that."

Niwa statistics show Greymouth saw more sunny days than Auckland across 2015, with its sunniest year in almost 70 years.

Timaru also took out the hottest nation-wide temperature of over 36.4 degrees in January.

Green said the whole South Island was hit with high temperatures, and this year looks very similar.