Waka Kotahi is urging South Island drivers to take particular care on the roads today with bad weather forecast in some areas, including the Southern Lakes and CentralOtago.

MetService has issued heavy rain warnings for Buller from 1-9pm today and for Westland south of Otira and Fiordland north of Doubtful Sound from 9am today until 6am on Monday.

It has issued a strong wind warning for the Canterbury High Country with gusts of up to 130km/h until 6am on Monday.

There is a heavy rain watch in place for the Marlborough Sounds, Nelson and Westland north of Otira and the headwaters of Otago lakes and rivers and a heavy wind watch for central Otago and Queenstown Lakes districts.

In a statement, Waka Kotahi said there was an increased risk of localised flooding, slips, and debris across the state highway network in these areas.

Drivers should regularly check the weather and their route before setting off, it said.

"Road users should drive to the conditions, use their headlights if visibility is poor, and watch their speed and following distances," it said.

High-sided vehicles and motorbikes should be especially careful travelling in strong winds, it said.