The MetService has issued a weather warning of heavy rain for Fiordland and Westland.
Up to 170 millimetres of rain is forecast for Fiordland and up to 200mm in Westland on Monday and Tuesday.
The rainfall is expected to feed into the headwaters of Canterbury rivers and lakes, which the MetService says has the potential to cause slips and surface flooding.
High winds gusting up to 120 kilometres an hour are also forecast for exposed parts of Southland and Clutha from late on Sunday until Monday morning.
