NIWA's Hotspot Watch
A weekly update describing soil moisture across the country to help assess whether severely to extremely dry conditions are occurring or imminent. Regions experiencing these soil
moisture deficits are deemed “hotspots”. Persistent hotspot regions have the potential to develop into drought.
Facts: Soil Moisture
For much of the North Island, soil moisture levels are near to even above normal for this time of year. There has been
little change from this time last week to soil moisture levels for nearly the whole of the island. The exception is for
coastal areas of South Wairarapa. Over the past week, soil moisture levels have decreased and the area of deficit has
expanded slightly north. Farther north and east, the effects of widespread and heavy rain from last week continue to be
felt from southeastern Gisborne through to Hawke’s Bay, where wetter than normal soils for this time of year exist.
In the South Island, soil moisture levels are much drier to severely drier than normal for this time of year for
northeastern Otago as well as for northern and southern sections of eastern Canterbury. Over the past week, this area of
severe to extreme dryness has grown slightly. Additionally, drier than normal soils for this time of year have developed
in the remainder of Otago, apart from southeastern coastal regions, as well as in portions of the West Coast,
southeastern Southland, Tasman and Nelson regions. Pockets of wetter than normal soil moisture for this time of year are
present from near Ashburton to Christchurch as well as in northern eastern Canterbury, around and south of Kaikoura. The
rest of the island is experiencing near normal soil moisture levels for this time of year.
Outlook
For the North Island, any rainfall is likely to be scattered after this weekend. Consequently, it’s likely that soil
moisture levels will decrease by next Friday with parts of Taranaki, northern Manawatu-Wanganui and western Waikato
trending toward drier than normal soils for this time of year. However, due to the antecedent conditions impacts should
not be significant. The exception is likely to be over the far southern and southeastern parts of the island, where
soils moisture may reach severely drier than normal levels for this time of year, particularly south of Masterton and
east of Wellington City.
For the South Island, rainfall should be significant enough from Southland, areas west of the Divide and possibly
portions of central Otago to alleviate any usual dryness and keep soils at near normal levels for this time of year.
East of the Divide, and for northern parts of the island, weekly rainfall is likely to be near or below normal.
Consequently, soil moisture levels are likely to decrease over the next seven days for much of the remainder of the
island with soils drying east of the Divide and the north of the island.
As a result, a hotspot exists in north and northeast Otago through to southern sections of east Canterbury. Another
hotspot is located in north-central parts of eastern Canterbury, roughly north of Christchurch and south of the Waiau
River.
ENDS