A hoar frost blanketed parts of Central Otago yesterday morning, creating an icy but spectacular start to the day in the Manuherikia Valley, near Lauder, and near Omakau.
The National Institute of Water and Atmospheric Research (Niwa) recorded -6.6degC at Lauder and -2.9degC at Alexandra, while an unofficial -4degC was recorded in Omakau.
Niwa meteorologist Seth Carrier said a hoar frost formed when there was more water vapour in the air than there was in ordinary frost - allowing the ice crystals to formmuch more intricate patterns.
"The frost forms similarly to dew, except that the air temperature and saturation point are both below the freezing point," he said.
Further up the road, towards Alexandra, a hoar frost had also formed but was still under a thick layer of fog by mid-morning.
