August 2019 was characterised by considerably lower than normal mean sea level pressure over and to the south of New Zealand. This set up resulted in a strong southwest airflow anomaly (i.e. more southwesterly winds) than normal across the country.
Temperatures were above average (0.51°C to 1.2°C above average) in parts of central Southland, north Otago, Taranaki, Whanganui, southern Hawke’s Bay, Waikato and the Coromandel. Temperatures were below average (0.51°C to 1.2°C below average) in parts of the West Coast, Tasman, Marlborough and Wairarapa.
Rainfall was above (120% to 149% of normal) or well above normal (>149% of normal) for western and southern parts of the South Island, as well as coastal North Otago, Manawatu-Whanganui, central Waikato and Auckland. Rainfall was below (50% to 79% of normal) or well below normal (<50% of normal) in parts of western Otago, the Mackenzie Basin, eastern Canterbury, Hawke’s Bay, Gisborne, Bay of Plenty and eastern Northland.
As of 31 August, soil moisture was near normal for most of New Zealand. Soils were drier than normal for isolated parts of inland north Otago, and wetter than normal about Kaikoura.
Percentage of normal rainfall for August 2019
End of month water balance in the pasture root zone for an average soil type where the available water capacity is taken to be 150 mm.
Departure from average air temperature for August 2019