Temperatures are expected to creep up during the next few days after an unseasonably cold start to the year.
WeatherWatch said the weather has felt more like spring than early January, as cooler and cloudier conditions spread across the country today.
Temperatures were well below average in many regions, mainly in the east and south of both islands, but also in Auckland and Northland.
The hottest region was the Bay of Plenty, where temperatures climbed into the mid-20s, but Wellington, Hamilton and Auckland all failed to top 20degC.
The South Island also had an unseasonably cold spell, with temperatures in parts of Otago, Canterbury and Southland failing to top 12degC.