Weather and Climate (1990) 10: 27-31 27 NEW ZEALAND WEATHER BRIEF REVIEW OF THE WEATHER (Fig. 1) WARMER THAN USUAL This was the third warmer than normal winter in a row, but not as warm as those of 1987 and 1988. In many places mean temperatures ranged from half to almost a degree above normal. They were near normal in Auckland, Bay of Plenty, Wanganui, Wellington, Otago and Southland. Rainfall totalling 115 to 140 percent of normal was recorded in much of Northland, Bay of Plenty, Buller and Nelson. It was drier than usual (rainfall 70- percent of normal) in western areas of Auckland, in Waikato, Wanganui, Gisborne, Hawke's Bay, the North Island Central Plateau, South Canterbury and coastal areas of North Otago. A total of 68 percent of normal rainfall was recorded at Timaru. By the end of the season some places in Central Otago had recorded over 50 consecutive days with little significant rain. The winter was sunnier than usual in Otago, South Westland and Fiordland, where total hours ranged between 110 and 125 percent of normal. Cloudier conditions prevailed about East Cape and Gisborne, where totals ranged between -90 percent of normal. Rainfall totals were about twice normal in Nelson and in some inland areas of Southland and Otago. It was also wetter than usual in Northland, Bay of Plenty, Manawatu, Wairarapa, Wellington and in most other regions of the South Island, except for coastal areas of South Canterbury and North Otago. Rainfall was below normal in Gisborne and Hawke's Bay. Rather cloudy conditions prevailed from East Cape to northern Hawke's Bay and in Wellington, Horowhenua and Manawatu. In 7 150 50 MONTHLY HIGHLIGHTS JUNE-AUGUST 1989 The first two weeks of June were much warmer than usual. Cooler conditions prevailed for the remainder of the month. Mean temperatures for the month were 1.3-1.7 C above normal in most eastern regions of the North Island. Maximum temperatures as high as 23 C were recorded at Kaikoura on the 7th and Napier Airport on the 12th. Minimum temperatures were as low as -9 C at Tekapo on the morning of the 30th. RAINFALL Fig. 1: Winter 1989. Rainfall map based on observations from 46 stations; temperature departure map based on observations from 40 stations; sunshine based on observations from 17 stations.
28 New Zealand Weather 7 110 90 TEMPERATURE Departure from Normal 4951-1 SUNSHINE these regions hours of bright sunshine were about 70- percent of normal. Mean sea level pressures as high as 1041.9 hpa were recorded at Oamaru Airport on the 29th. This reading was the highest recorded at Oamaru in over 29 years of record. The first week of July was mostly warmer than usual, but rather cool conditions predominated over the last two weeks. Fine frosty weather prevailed in many places toward the end of the month. It was also a month without much wind. Minimum temperatures as low as -10 C were recorded at Arthur's Pass on the morning of the 27th. There were four consecutive days with ground frost recorded at Wellington, Kelburn from the 28th. This event was the most severe since four days in August 1951. The month was drier than usual over much of New Zealand, especially in parts of South Canterbury, where totals were only 35-40 percent of normal. Hours of bright sunshine were well above normal in many places. A total of 153 hours (150 percent of normal) was recorded at Waingawa, making this the sunniest July there since records began in 1935. Departures were 130-135 percent of normal in Taranaki, Manawatu, Wellington and eastern regions of the South Island as far south as Otago. August was another month without much wind. There were no 'windy' days (i.e. days with wind gusts to at least 63km/h) at Christchurch Airport, which was the first recorded incidence there in August in at least 35 years. Rainfall totals were about twice normal in parts of Northland. It was very much drier than usual in Central Otago (rainfall 5-25 percent of normal) and Southland (rainfall 25-40 percent of normal). A total of 2mm (7 percent of normal) was recorded at Lauder, where up to the end of the month there had been 51 days with little significant rain (i.e. not more than lmm on any of the days when it did rain). Mean temperatures were above normal over much of the country, especially in Buller and Westland where they were 1.3-1.7 C above normal. Record high temperatures for August occurred on the afternoon of the 24th in places in Auckland, Waikato, Bay of Plenty, Taranaki and Wellington. The highest of these were 22 C at Kawerau and Hamilton where records began in 1954 and 1921 respectively. A temperature of 21 C was recorded in Auck-
New Zealand Weather land, which was the highest in August in the City since records began in 1868. Hours of bright sunshine were -140 percent of normal in Southland and Fiordland. The total of 169 hours (137 percent of normal) measured at Invercargill was the highest in August since records began in 1932. It was rather dull in North Canterbury and along the Kaikoura Coast where hours were 70- percent of normal. A low total of 100 hours (70 percent of normal), recorded at Christchurch was the lowest equal since records began in 1949, and total of 104 hours (69 percent of normal) recorded at Kaikoura was the lowest for August since records began in 1960. (Fig. 2) UNUSUALLY WARM Spring 1989 was much warmer than usual. The mean temperature for New Zealand was 13.2 C which was 1.1 C above the 1951- normal. This was the second warmest spring, equal with that of 1893. The warmest spring season occurred last year with 13.3 C. Record high mean temperatures for spring were recorded in places in Auckland, Taranaki and along the west coast of the South Island. At Hokitika the mean of 12.8 C, which was 1.7 C above normal, was the highest since records began in 1866. Mean temperatures were 1.5-2.0 C above normal in Auckland, Gisborne, Wairarapa and Westland, and 1.0-1.5 C above normal in most other places. They ranged from near normal to 0.5 C of a degree above normal in Otago. The warmer temperatures were caused by frequent north-easterly airstreams over New Zealand. These also contributed to wetter conditions over much of the North Island, especially in northern and eastern regions, along the Kaikoura Coast and in North Canterbury, where totals were up to twice normal. Rainfall totalling 407 mm (237 percent of normal) measured at Kaikoura was the highest since records began in 1949. Totals ranged from 40-60 percent of normal in inland high country regions of the South Island, and in parts of South Canterbury. It was also drier than normal in Southland and along the West Coast of the South Island. Hours of bright sunshine were well below normal in Northland, Bay of Plenty and Marlborough, and well above normal in Fiordland and Southland. MONTHLY HIGHLIGHTS SEPTEMBER-NOVEMBER 1989 September was another month without much wind. Frequent north-easterly airstreams kept temperatures warmer than usual, especially in Westland. They also contributed to drier and sunnier than normal conditions in western regions of New Zealand south of Waikato, and in the far south of the South Island. There were no 'windy' days (days with gusts to at least 63 km/h) at both Dunedin and Invercargill Airports.This was the first recorded incidence at Invercargill in September for 32 years. The mean temperature for New Zealand of 11.5 C was 1.2 C above normal and the second highest on record. Mean temperatures were 2.0-3.0 C above normal in Westland. Hundred-year records for maximum temperatures were broken at Hokitika on the 9th when the temperature reached 22.8 C, and at Wellington, Kelburn on the 26th with 21.1 C, where records began in 1866 and 1862 respectively. Low rainfall totals of near to 10 percent of normal were recorded in Wellington and coastal areas of Southland. Only 9 mm were recorded in Wellington (9 percent of normal) and Invercargill (12 percent of normal) which were the lowest totals for September since records began in 1862 and 1934 respectively. Rainfall of twice to almost three times normal was recorded in areas from Poverty to Hawke's Bay, and almost four times normal along the Kaikoura Coast where there were many slips. The total of 242 mm (266 percent of normal) at Gisborne was the highest in September since records began in 1937. Hours of bright sunshine were well above normal in Taranaki, Westland, Fiordland, Southland and Otago. It was rather dull from East Cape to Poverty Bay, along the Kaikoura Coast, and in Marlborough. October was much warmer than usual. Frequent northerly airstreams contributed to cloudier than normal conditions in northern 29
30 and western regions of both Islands, and sunnier than normal conditions in the far south of the South Island. The mean temperature for New Zealand was 13.4 C which was 1.3 C above normal. This was the warmest October in over 25 years, and the fourth equal warmest since records began in 1853. New October temperature records occurred in the east of the North Island and the west of the South Island. The mean temperature at Gisborne Airport of 15.5 C (2.0 C above normal) was the highest since records began in 1937 and the mean of 12.7 C at Hokitika (1.5 C above average) was the highest since records began in 1866. Rainfall was above normal in many regions. It was particularly wet in Bay of Plenty, along the Kaikoura Coast and in North Canterbury, where totals were twice to three times normal. Record high rainfalls were recorded at Kinleith with 387 mm (276 percent of normal), Kaikoura with 160 mm (258 percent of normal), and Christchurch Airport with 138 mm (321 percent of normal). Records New Zealand Weather in these places began in 1967, 1949 and 1947 respectively. It was rather cloudy in Bay of Plenty where hours of bright sunshine were only 60-70 percent of normal. At Rotorua sunshine totalled 118 hours (62 percent of normal), which was the lowest in October for 32 years, and the second lowest since records commenced in 1930. November was another month with above normal temperatures. The first three weeks wer much warmer than usual. Cooler conditions prevailed over the last week. Very high temperatures for November were recorded throughout Canterbury and Otago from the 7th to the 9th in hot dry, northwesterly conditions. The highest of these was 31 C, on the 9th at Timaru Airport. This was the highest recorded there in over 28 years of record. It was also just 3 C lower than the highest November temperature ever recorded iin New Zealand, which was 34 deg C at Hastings in 1949. Mean temperatures for the month were almost 2 C above normal in places in Waic C 150 +1.0 +0.5 0.5 50 RAINFALL TEMPERATURE Departure from Normal (1951-) Fig 2: Spring 1989. Rainfall departure map based on observations from 46 stations; temperature departure maps based on observations from 38 stations; sunshine based on observations from 19 stations.
New Zealand Weather 3 1 rarapa and South Westland, and about 1 to 1.5 C above normal in most other places. The mean temperature for Waingawa (Masterton) of 15.6 C was 1.8 C above normal and was the highest since records began in 1906. Rainfall was well above normal in Auckland, Gisborne and Hawke's Bay where totals were about twice normal. They were three times normal at East Cape. It was particularly dry in South Canterbury and Central Otago, where totals ranged from 10 to 40 percent of normal. The total of 7 mm (13 percent of normal) recorded at Timaru was the lowest measured there in November since records began in 1897. 110 90 SUNSHINE Many thanks are due to the New Zealand Meteorological Service for providing the climatological information from which this summary was compiled. S. M. Burgess