Current climate – October 2015

October 2015 was characterised by air pressures which were higher than normal over southern Australia, the Tasman Sea and New Zealand and lower than normal to the south-east of New Zealand.  This resulted in more south-westerly airflows over New Zealand than is normal for the time of year.

Rainfall

This southwest flow anomaly (typical of El Niño at this time of year) was clearly illustrated by the rainfall anomalies observed across New Zealand for October Rainfall was below normal (50-79%) or well below normal (< 50%) for the majority of the North Island, as well as northern, eastern and inland parts of the South Island north of Otago.  Conversely, rainfall was above normal (120-149%) or well above normal (> 149%) for south-eastern parts of the South Island, Fiordland and southern Westland.

Temperature

October temperatures were above average (+0.51°C to +1.20°C) or well above average (> +1.20°C) throughout the South Island, with the exception of the West Coast.  Similarly, temperatures were above average in parts of Auckland, Bay of Plenty, Gisborne, Hawke’s Bay and the Kapiti Coast.  Temperatures were typically near average (within 0.50°C of average) for remaining parts of New Zealand. 

Sunshine

A sunny October for eastern and southern parts of the North Island as well as eastern and central areas of the South Island, with above normal (110-125%) or well above normal (> 125%) sunshine recorded in many of these areas.

Soil Moisture

As of 1 November 2015, soil moisture levels were typically below normal for much of the North Island, as well as for most eastern, inland and northern parts of the South Island.  The notable exceptions were northern Wairarapa and the south-eastern South Island where soil moisture levels were above normal for the time of year.

Percentage of normal rainfall for October 2015
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 October 2015.