The drop in temperatures beginning Monday will hit across the North Island.
Whangārei can expect to fall from a high of 18C today to 15C by Tuesday, while Tauranga will drop from 18C today to 14C on Tuesday.
Hamilton and New Plymouth will go from rainy highs of 16C today to highs of 13C on Tuesday, while Gisborne will be rain free but fall from 18C today to 13C on Tuesday.
Wellington residents can expect drizzling rain and a high of 13C today before isolated showers and a high of 10C on Tuesday.
The capital's temperatures would be a sharp drop from yesterday when Wellington hit a high of 17C and the Kapiti Coast was 6C above average for June with a top of 19C, MetService said.
In the South Island, Nelson was also 6C above its June average when it also hit a high of 19C yesterday.
After some morning rain today and a high of 16C, Nelson temperatures will continue dropping next week although the skies will be clear and fine as the city hits a top of 13C on Tuesday.
Christchurch can expect light rain today and a top temperature of 12C. Highs of 10C and overnight lows of 1C are expected for the start of next week.
Dunedin is tipped to hit a high of 12C today. Cloud and a high of 10C are expected on Tuesday.
Today's weather
Whangārei - A few showers, mainly around the middle of the day. Southwesterlies. High 18C, Low 11C
Auckland - A few showers. Southwesterlies picking up. High 17C, Low 12C
Hamilton - A few showers, cloud breaking this afternoon. Southwesterlies. High 16C, Low 8C
Tauranga - Cloudy periods. Southwesterlies. High 18C, Low 10C
Rotorua - Cloudy periods. Southwesterlies. High 15C, Low 7C
New Plymouth - Occasional showers. Southwesterlies picking up evening. High 16C, Low 10C
Napier - Partly cloudy. Southwesterlies. High 17C, Low 7C
Whanganui - Occasional showers. Westerlies developing this morning. High 16C, Low 11C
Wellington - Occasional drizzle, turning to rain for a time around midday, then fine spells increasing. High 13C, Low 8C
Nelson - Some morning rain then fine. Southwesterlies developing. High 16C, Low 7C
Christchurch - Light rain at times, clearing by early evening. Southwesterlies. High 12C, Low 2C
Dunedin - Cloudy and drizzly, clearing this morning then fine. Southwesterly. High 12C, Low 5C