A wintry blast of snow closed the Rimutaka Hill Rd for several hours yesterday.
The road was closed in the early hours of the morning and remained closed until about 9.30am as contractors swept snow from the road and cleared a minor slip on the Featherston side of the hill.
Drivers headed to Wellington faced a long queue, with vehicles backed up all the way into Featherston.
NZTA Wellington regional performance manager Mark Owen said contractors would monitor the road 24/7, with shifts stationed on the hill if necessary.
"They have worked hard to get it open reasonably quickly, which is really good. Obviously we've got the snow to deal with and there's potential for ice in some areas as well."
Snow had reached depths of about 10cm at the summit and extended as far as Jim's Corner on the southern side and about 8km down the northern side of the hill. A MetService camera at the summit would help give road crews advance warning of the weather as more snow was forecast over the next few days.
Drivers were being warned to use extreme caution as the wind chill factor on the hill created "slushy snow", Mr Owen said. "Take care and be aware the road could close at any time."
Meanwhile youngsters on school holiday headed to the summit for snowball fights and a chance to play in the snow.
MetService meteorologist John Law said Wairarapa could expect more wintry showers today, with the possibility of snow above 100m and strong southerlies forecast for the coast. Weekend weather was expected to be drier but still cold, showers clearing on Saturday. Weekend temperatures were expected to fall overnight, with "pretty decent frosts", Mr Law said.