A motorist is urging drivers to exercise extreme caution while travelling on State Highway 8 through Lake Tekapo.

He reported encountering black ice on the road, which created hazardous driving conditions.

The motorist, who was driving south, said the ice took him by surprise and has since notified emergency services.

At 8 AM, the temperature in the Lake Tekapo area was a frigid -3°C.

The road was still open as of 8AM.