Motorists are being urged to check weather conditions following a close call in a flooded river north of Lake Ohau.
Two men and two children were yesterday rescued by helicopter after the four-wheel-drive they were in overturned in Hopkins River, south of Aoraki/Mt Cook National Park.
Senior Search and Rescue officer Tracy Brickles says it could have gone a lot worse.
"[They were] very lucky - the weather was very bad at the time."
MetService has a severe weather warning out for Fiordland, Westland, and the Canterbury Headwaters with heavy rain forecast.
Brickles said a rescuer swam out and secured the car with rope - and the rescue effort went well from there.
"The people who needed rescuing, they stepped onto the helicopter. The helicopter managed to hover close to the vehicle and they could climb in."
Brickles is asking people heading outdoors this weekend to check the forecast, particularly if they're heading into the hills or bush.
"They should always be prepared for every eventuality that they might come across, and have their beacon correctly registered."
Hiker's rescue just as miraculous
Police are also praising the efforts of rescue teams who they say saved a hiker's life at Mt Ngauruhoe.
A 27-year-old man became stranded at the summit after separating from friends doing the Tongariro Alpine Crossing.
Snr Const Barry Shepherd says two search teams battled terrible conditions.
"They've ditched their Saturday night plans with a moment's notice and responded to help this poor chap… pretty admirable."
Shepherd says the man suffered mild hypothermia.
"At the top of Mt Ngauruhoe, it's 2100m above sea level. It's snowy, and they've done a fantastic job."
Shepherd says rescuers faced zero visibility, strong winds and freezing temperatures.
"They were… not able to see or hear him. It was just a matter of yelling out and flashing their torches around and eventually finding him. There were a few nervous moments there."