Fire and Emergency New Zealand (Fenz) has placed Central Otago under a total fire ban and has restricted fires in most of the rest of the South.
Fenz district manager Otago Phil Marsh said the days were continuing to get drier.
"It is expected to be like this for the coming months," Mr Marsh said.
Dunedin, Clutha, Strath Taieri, Upper Waitaki, Coastal Waitaki, Southland and the West Coast were moved into a restricted fire season, meaning a permit was required to light an open fire.
Previous fire seasons had shown large vegetation fires could ignite and spread quickly in dry weather, Mr Marsh said.
Anyone with a permit needed to comply with conditions.
"We are restricting the fire season to reduce the risk of fires getting out of control, particularly with the influx of holidaymakers in the district ... please do your bit this summer to keep everyone safe," Mr Marsh said.
Fenz Southland district manager Southland Julian Tohiariki said anyone planning to do activities that could cause a spark, such as mowing or other hot works, should do them in the cooler parts of the day to reduce risk.
Niwa weather data shows 30mm-50mm of rain fell in interior Otago and southern Fiordland this week, and the rest of the region had much lighter rainfall — generally less than 25mm.
The low rainfall was causing soil moisture to decrease moderately and the driest soils in the South Island, compared to normal for this time of the year, are the upper West Coast, Banks Peninsula, Fiordland, coastal Southland and Stewart Island.
High pressure is expected be present in the South next week, resulting in more dry weather and further decreases in soil moisture levels.
Hotspots in the eastern and lower South Island were likely to strengthen and expand, the data shows.
