A dry month for the South Island with warm and wet conditions in the North.
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Rainfall
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Below normal (50-79%) rainfall was recorded for much of the South Island with pockets of well below normal (< 50%) rainfall observed in some locations. Conversely, above normal (120-149%) September rainfall occurred in several North Island regions including parts of Auckland, Bay of Plenty, Gisborne, Hawke’s Bay, Manawatu- Whanganui and Taranaki. |
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Soil Moisture |
As of 1 October, 2014 soil moisture levels on the east coast of the South Island were below normal for the time of year, while levels for the remainder of the South Island were near normal. Soil moisture levels in the North Island were at field capacity and were slightly wetter than normal in the Hawke’s Bay. |
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Sunshine |
A sunny September for the South Island with above normal (110-125%) sunshine recorded. Near normal (90-109%) sunshine for the North Island, Marlborough and Nelson. |
Overview
September 2014 was characterised by lower pressures than normal over the north-east of the country and higher pressures well to the west of New Zealand. This pressure pattern brought about more south-easterly flows across northern New Zealand.
A long reigning dry spell in many parts of the South Island began in mid-August and persisted into the first half of September, contributing to the south experiencing a dry September as a whole. Overall, rainfall was largely below normal (50-79%) for the Island and well below normal (< 50%) in parts of the Queenstown Lakes district. Conversely, rainfall was above normal (120-149%) in several North Island regions including parts of Auckland, Bay of Plenty, Gisborne, Hawke’s Bay, Manawatu- Whanganui and Taranaki. Rainfall was generally in the near normal range for the remainder of the North Island as well as the Tasman and Nelson regions of the South Island.
Soil moisture levels were slightly lower than normal along the West Coast, Tasman and Taranaki at the start of the month and have become drier this month due to lack of significant rain. While soil moisture along the West Coast began to slightly replenish from 12 September onwards, drier conditions in the east of the Island sparked the rapid depletion of soil moisture levels during the second half of September. As of 1 October, 2014 soil moisture levels on the east coast of the South Island were below normal for the time of year, while levels for the remainder of the South Island are near normal. Soil moisture levels in the North Island were at field capacity and were slightly wetter than normal in the Hawke’s Bay as a result of the abundant rainfall in the region during September.
It was a mild September for Auckland, Waikato, Bay of Plenty, Manawatu-Whanganui, Taranaki and parts of the West Coast with above average (0.51 to 1.20°C) temperatures recorded. It was particularly warm in the north of the South Island on September 24th, when higher pressures and a north easterly flow brought about near-record high temperatures at several locations. Coastal Otago was not as warm during September and was characterised by below average temperature (-1.20 to -0.51°C). Generally near normal temperature was experienced elsewhere. The nation-wide average temperature in September 2014 was 10.9°C (0.50°C above the 1971-2000 September average from NIWA’s seven station temperature series which begins in 1909)[1].
It was a sunny start to spring for most of the South Island, reflecting the dryness experienced during September. Several stations in the south received near-record sunshine hours, with Queenstown enjoying its highest September sunshine total on record following on from the sunniest August last month. The North Island along with Nelson and Marlborough were not as bright in September and received near normal (90-109%) sunshine levels.
Further Highlights:
- The highest temperature was 24.1°C, observed at Leeston on 11 September.
- The lowest temperature was -6.9°C, observed at Middlemarch on 28 September.
- The highest 1-day rainfall was 113.6 mm, recorded at Lake Moeraki on 12 September.
- The highest wind gust was 170 km/hr, observed at Cape Turnagain on 26 September.
- Of the six main centres in September 2014, Auckland was the warmest, Christchurch was the coldest and driest, Hamilton was the cloudiest and wettest and Dunedin was the sunniest.
- Of the available, regularly reporting sunshine observation sites, the sunniest four centres[2] so far in 2014 (January to September) are: Whakatane (1992 hours), Lake Tekapo (1792 hours) Tauranga (1786 hours) and Nelson (1750 hours).
For further information, please contact:
Mr Chris Brandolino NIWA Forecaster – NIWA National Climate Centre Tel. 09 375 6335, Mobile (027) 886 0014
Download the full report:
Climate Summary September 2014 [543.7KB]
Climate statistics table:
Climate statistics for September 2014 [69Kb PDF]