A short spell of cooler, wet weather is expected to cross the country in the next few days, followed by a return of the warmer, dry conditions that have dominated many areas.
The rain isn’t expected to do much to dampen drier than usual soils through much of the west and central North Island, and in many central and eastern parts of the South Island.
Niwa’s drought index shows parts of coastal Otago as very dry, with much of the rest of Otago classed as dry. Central parts of the upper South Island are also dry, as is a stretch of the West Coast, including Graymouth and Hokitika. In the North Island, an area of western, central Waikato is classed as dry.
MetService is forecasting a cool and rainy change on Sunday and Monday, before another high pressure system arrives next week with a return to settled weather.
The approach of a frontal system late Saturday into Sunday would bring rain for the west and south of the South Island, extending to parts of the North Island on Monday, MetService meteorologist Mmathapelo Makgabutlane said.
The fronts would bring a cool change that spread across the rest of the country early next week.
“Most people can look forward to a fresh 3-5C drop in temperatures which will be noticeably cooler than what we’ve been having,” Makgabutlane said.
A steady high pressure system during the start of May had brought unseasonably warm temperatures for many places.
On Wednesday Wellington Airport recorded 21.1C, 0.9C below its highest ever temperature for May in records back to 1972.
“Another area of note is the lower South Island which will continue to be 5-6C higher than average for this time of year until the end of the weekend,” Makgabutlane said.
On Friday, 21.5C was recorded at Invercargill Airport, the warmest temperature recorded at the site since the weather station there was set up in 1948.
Auckland is forecast to have a fine weekend with light winds and highs around 20C. Some rain is forecast by Monday night, then a few showers Tuesday morning. Daytime highs could edge a few degrees lower later in the week with the arrival of southerlies.
Wellington could have a few spots of drizzle by Sunday, then rain on Monday and showers on Tuesday and possibly Wednesday. Strong southerlies are forecast for Tuesday, and the daytime high is expected to drop to 14C on Wednesday.
Low cloud is forecast to clear in Christchurch on Saturday morning, but rain or showers are forecast for the following three days. Southwesterlies are expected to develop on Monday and the temperature is expected to reach just 13C on Tuesday.
In its Hotspot Watch, published on Friday, Niwa said only 5mm of rain or less had fallen across most of the North Island in the past week. No rain at all had fallen in many parts of eastern and central North Island.
While heavy rain had fallen along much of the West Coast, amounts of 5mm or less were common in the east of the South Island, Niwa said.
In the coming week, the upper North Island wasn’t expected to get more than 15mm of rain, while up to 25mm could fall elsewhere in the North Island, and more than 30mm was possible in some coastal pockets.
Much of the West Coast could get 50-100mm of rain in the coming week, while the upper South Island could get up to 25mm, but only 15mm or less was expected in the lower South Island.
Dry areas in Waikato, Canterbury and Otago could strengthen and expand.