Extended warmth for South Island
A large area of high pressure will take up residence east of New Zealand for the next few days, bringing more unusual springtime warmth to parts of the South Island from tomorrow through to late next week, says NIWA forecaster Seth Carrier.
The high will produce several consecutive days of northerly winds, delivering an extended warm stretch to residents of the South Island, especially east of the Alps.
Mr Carrier said maximum temperatures may be more than 10 degrees above average for up to to six consecutive days across inland Canterbury, Otago, and Southland, with actual air temperatures surging well into the 20s from late this weekend.
These are the same regions that saw temperatures reach into the upper 20s (along with a 30.1 degree reading at Otematata) last week, but instead of two days of unusual warmth, this upcoming episode will be substantially longer.
In addition to the heat, little if any rain is expected across the eastern and southern South Island during the next week.
"It has already been a very dry month across the lower South Island, with many locations recording well below normal rainfall.
"In fact, Queenstown recently ended a 30-day dry spell*, its longest since February-March 2013," - Seth Carrier.
*A dry spell is at least 15 days with less than 1 mm of rain per day.
Forecast for Auckland Marathon
This year’s Auckland Marathon is on Sunday morning, and the weather will mostly cooperate for the thousands of runners. Helpfully, there is likely to be at least partial cloud cover, along with the chance for a couple isolated showers. Winds are also expected to be light, coming from the northeast at less than 20 km/h.
Unfortunately, there will be some humidity on Sunday morning as the high pressure east of the country directs a moist air mass toward the upper North Island. Look for a temperature at the start of the race near 15°C, climbing to 18-19°C by midday.