Drivers on South Island highways are being advised to exercise caution as a cold snap brings snow and flooding to the region. The weather warning comes as temperatures drop sharply, prompting concerns over road safety. Officials have issued alerts to drivers, urging them to slow down and avoid unnecessary travel. The sudden change in weather has led to hazardous conditions on key routes, with reports of icy patches and flooded roads. Emergency services are on standby to assist drivers in distress, while local authorities are monitoring the situation closely. The cold snap is expected to last for several days, increasing the risk of further disruptions.