A severe weather warning has been issued for Clutha, Southland and southern Fiordland, with snow showers hitting the region.

MetService said they become heavier and more persistent from nine tonight, through until the same time tomorrow.

Snow has already started falling in some higher parts of the district, as well as lower down in the Catlins.

Tahakopa Valley Road, in the Catlins, is now closed due to snow.

Motorists are advised to drive to the conditions and to check the roads before leaving home tomorrow morning, as contractors will not be able to clear roads until conditions improve.