Current climate: January 2017

January 2017 was characterised by significantly lower mean sea level pressure than normal over and to the south of New Zealand. This atmospheric pressure setup caused more southwesterly winds than normal across the country, which encouraged the passage of storms and low temperatures for much of New Zealand throughout the month.

Rainfall

Significant dryness in eastern North Island, well below normal rainfall (<50% of normal) in Gisborne, Hawke’s Bay and Northland. Above normal (120-149% of normal) or well above normal (>149% of normal) rainfall for West Coast, middle and south-coastal Canterbury, Otago, inland Southland, Wellington and Manawatu-Whanganui.

Temperature

Well below average (< -1.20°C of average) or below average (-1.20°C to -0.50°C of average) temperatures for most of the South Island and south and west North Island. Near average (-0.50°C to +0.50°C of average) temperatures for eastern areas and well above average (>1.20°C of average) for a small number of locations in Hawke’s Bay.

Sunshine

Near (90-110% of normal) or above normal sunshine (110-125% of normal) in eastern areas of the North Island and for parts of eastern Canterbury. Below normal (75-89% of normal) or well below normal (<75% of normal) sunshine for west and south of both North and South Islands.

Soil Moisture

As of 1 February, soil moisture levels were much lower than normal across most of the North Island, particularly in Northland, eastern Waikato, Coromandel, inland Bay of Plenty, East Cape, and Hawke’s Bay. Soils were also drier than normal for coastal northern Canterbury. Soils were wetter than normal for the time of year for Tasman, West Coast, Otago and Southland, and near normal soil moisture levels were observed elsewhere.

Departure from average air temperature for January 2017.
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.
Percentage of normal rainfall for January 2017.