Current Climate - February 2013

February 2013 was characterised by anticyclones ('highs') which were slow moving over New Zealand. These highs, or anticyclones, kept rain-bearing weather systems such as lows and fronts away, resulting in an extremely dry and sunny February for many regions of the country. 

Rainfall

February rainfall totalled less than 15 mm (and also less than 15 percent of February normal) in parts of Northland, Auckland, and the Bay of Plenty. It was the driest February on record for Leigh (north Auckland), and Milford Sound. In the case of Leigh, it was also the driest month (of any month) in records which began in 1966.

The dryness was widespread. Rainfall was less than 25 percent, or a quarter, of February normal around Taupo, in parts of Gisborne and Hawkes Bay, and along the West Coast of the South Island. Less than half (50 percent) of normal February rainfall was generally observed across the remainder of the country. The exceptions were between Wanganui and Wellington, in Central Otago and the Lakes District (with near normal rainfall); and Marlborough and the Kaikoura coast (with rainfall between 50 and 80 percent of February normal).

As at 1 March 2013, extreme soil moisture deficit (more than 130 mm of deficit) was evident in Northland, Auckland, Waikato, the Bay of Plenty region (including Taupo), Gisborne, Hawkes Bay, Wairarapa, between Wanganui and Palmerston North, parts of Marlborough, Canterbury, and Central Otago. Significant soil moisture deficit (more than 110 mm of deficit) was generally observed elsewhere in the North Island, as well as in the Waimea Plains, and across eastern Otago. An adverse event due to drought was declared in Northland on 27 February.

Temperature

Mean temperatures in February were above average (between 0.5°C and 1.2°C above the February average) across the west and south of the South Island, as well as in inland regions of the North Island. In contrast, below average February temperatures (between 0.5°C and 1.2°C below the February average) were observed around the Kaikoura Coast, as well as the east coast of the North Island. Elsewhere, mean temperatures were near average (within 0.5°C of the February average). The nation-wide average temperature in February 2013 was 17.1°C (0.2°C below the 1971-2000 February average), using NIWA's seven-station temperature series which begins in 1909.

Notably, however, in most regions, afternoon temperatures were typically well above February average, and morning temperatures below February average, due to the clear skies and relatively light winds associated with the prevailing high pressures.

Sunshine

The dominance of high pressures during February resulted in an extremely sunny month across New Zealand. Sunshine totals were well above normal (exceeding 125 percent of February normal) across most of the North Island (south of Auckland), on the West Coast South Island, along the Southern Alps, as well as north Canterbury and the Kaikoura coast. Elsewhere, sunshine totals were also above normal (between 110 and 124 percent of February normal). It was the sunniest February on record for numerous locations across both Islands. Notably, Wellington and Hamilton recorded their sunniest February on record, Tauranga experienced its second sunniest February, Christchurch observed its third sunniest February, and Dunedin recorded its 5th sunniest February. 

Percentage of normal rainfall for February 2013.
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 February 2013.