The Bay of Plenty is on heavy rain watch as a slow-moving front moves up the country.

Heavy rain is expected about the Eastern Bay of Plenty ranges this afternoon through to the evening.

A bitter southerly flow is moving up the country bringing cold temperatures to the Bay of Plenty.

Periods of rain is also expected for the Western Bay of Plenty this afternoon.

The MetService is predicting temperatures to drop in the Bay with an approaching bitterly cold southerly flow spreading northwards.

Overnight lows of 6C and 2C are being forecast for the next few days, with daily highs sitting around the 10 degree mark.

Snow showers have already fallen across parts of southern New Zealand and the forecast for the week keeps hold of these wintry showers. 'It's shaping up to be a cold week,” says meteorologist John Law commented. "The combination of these cold temperatures with the showery airstream moving across New Zealand does mean we are likely to have snow falling to lower levels in many places."

Even the far north of the country will experience the temperature falling away this week, with the cold air reaching Northland and Auckland during Wednesday, leading to some cold days and even colder nights.

Temperatures across these northern parts of the country are widely forecast to dip back down to 3 or 4C overnight Wednesday, while parts of Waikato and the Central Plateau are forecast to drop back down below freezing, says John. The central parts of the South Island are also forecast to see cold temperatures both day and night.

However, the temperatures are not expected to drop to those record-breaking temperatures that were recorded in June.

'Look out for more cold nights coming up across inland Canterbury and Otago,” says John.

'But without a deep layer of snow to keep the lower levels of the air incredibly cold, temperatures are forecast to drop to -9 or -10C for the likes of Twizel, rather than the -20C that was recorded last month.”