Following the exceptionally strong high pressure system at the beginning of this week, more high pressure systems are lined up to cross the Tasman, bringing warm air from Australia.
MetService and the National Institute of Water and Atmospheric Research both pick above-average temperatures over the coming days, especially in the east of both islands.
Afternoon temperatures above 20 degrees are expected here, along the east coast from East Cape to Canterbury.
The afternoon highs get a boost from the Föhn effect as winds sweep down from inland hills.
(Descending air compresses as the molecules are squeezed closer together and friction causes heat.)
No significant rain is on the horizon over the next week and a half.
With sunny days and wind, the process of evapotranspiration (loss of soil moisture) will pick up.
As of yesterday moisture loss over the past week has averaged 2.4 millimetres a day, and this can be expected to increase in the days ahead.
The current soil moisture deficit is around 45mm.
Despite some rain on Sunday and Monday the month so far has had just 13.3mm - well short of the 30-year average for September of 71mm.
