UPDATED 2.44PM: State Highway 29, over the Kaimai Range, is open to all traffic this afternoon.

The New Zealand Transport Agency reports all vehicles are now able to travel over the summit.

Rain and strong winds are causing adverse weather conditions on SH29. File photo.

The highway was closed earlier today due to high winds on the summit which posed a potential tipping danger for some vehicles.

Detours through Rotorua and Katikati were put in place.

While the road is open, motorists are being warned of slippery conditions and are asked to drive accordingly.

Earlier:

State Highway 29, between Tauranga and Matamata, is closed to large vehicles.

High winds over the Kaimai Range poses a danger for large vehicles such as heavy trucks or buses, say police.

'Traffic will be re-directed at Lower Kaimai until further notice.”

Heavy vehicles heading westbound are advised to use SH36 towards Rotorua, then onto SH5 and then onto SH28, and back to SH29.

Heavy vehicles heading east are to use SH28, south towards SH5, then onto SH36 back towards Tauranga and then back to SH29.

This detour will add a further 80 minutes to travel time.

There are also reports of a large tree down in the area partially blocking one lane.

Motorists are being asked to drive with care as continuous rain means the roads will be slippery.

The MetService is predicting heavy falls about eastern areas from Northland to Western Bay of Plenty.

'For western Bay of Plenty and Mount Taranaki 70 to 100mm may accumulate, while for northwest Nelson and Buller, 100 to 130mm of rain is possible about the ranges.”

The adverse weather is being caused by a strong and moist north to northeast flow moving over the North Island.

'People, especially those planning outdoor pursuits, are advised this rain will cause rivers and streams to rise rapidly, with slips and flash flooding also possible. Driving conditions will also be hazardous,” warns the MetService.

Rain is expected to ease sometime tomorrow.