Summer 2001-02
Monday, 4 March 2002
Extremely wet in the south and west of the North Island and eastern regions from Gisborne to Canterbury
Below average rainfall in some southern South Island areas
Very warm on the West Coast of the South Island; Cool in many eastern regions
Very cloudy in Wellington and Canterbury
Many North Island and most eastern districts received at least one and a half times their normal summer rainfall, and experienced one of the wettest and most unsettled summers on record. Rain occurred on more than half of the days in some northern, western and southern North Island regions, and Nelson. Rainfall was below average in parts of Fiordland and south Westland, and below average totals in inland Southland resulted in significant soil moisture deficits there. Moderate soil moisture deficits prevailed in Central Otago.
Summer was warmer than usual on the South Island West Coast with mean temperatures about 1.0°C above normal. It was also warmer than normal in parts of Auckland, Waikato, Taranaki, Southern Lakes and Southland. Cloudiness associated with cool onshore winds produced a cool summer with temperatures at least 0.5°C below normal in Hawke’s Bay, and the east of the South Island from Marlborough to south Canterbury. The national average temperature of 16.6°C was the same as the mean summer temperature for the period 1961-1990. However December was very warm and February was rather cool.
Sunshine was below average over much of New Zealand, especially in Wellington and Canterbury. However, Taranaki, Westland and Southland measured near average sunshine hours. Other features of the summer were a higher than average frequency of thunderstorms and heavy rainfall events, along with a two significant southerly storms, a few hailstorms, and a tornado.
The summer’s climate pattern was dominated by many more depressions (‘lows’) than usual in the Tasman Sea, and across New Zealand, with above average pressures to the south. These features resulted in more frequent easterly winds over the South Island.
Extremely wet in the south and west of the North Island and eastern regions from Gisborne to Canterbury
Rainfall was at least 150 percent (one and a half times) of normal in the south, west and east of the North Island, and from Marlborough to Canterbury. Many locations in these regions experienced one of their wettest summers on record. Rainfall was also above average, with totals at least 120 percent of normal, in most other North Island regions, as well as in Buller, north Westland and Nelson.
Near or record high summer rainfall was recorded at:
| Location | Summer rainfall (mm) |
Percentage of normal | Year records began | Comments |
|---|---|---|---|---|
| Whitianga Airport | 454 | 145 | 1988 | 2nd highest |
| Te Puke | 506 | 137 | 1973 | Very high |
| Whakatane | 392 | 173 | 1997 | 3rd highest |
| Turangi | 522 | 151 | 1968 | 3rd highest |
| Hicks Bay | 492 | 199 | 1991 | 2nd highest |
| Motu | 686 | 164 | 1991 | Highest |
| Mahia | 369 | 208 | 1991 | 2nd highest |
| Napier Airport | 360 | 196 | 1951 | 3rd highest |
| Whakatu | 379 | 275 | 1983 | Highest |
| East Taratahi | 252 | 172 | 1973 | 2nd highest |
| New Plymouth | 762 | 245 | 1863 | 2nd highest |
| Palmerston North Airport | 357 | 166 | 1944 | 3rd highest |
| Wellington, Kelburn | 491 | 214 | 1862 | 3rd highest |
| Farewell Spit | 485 | 214 | 1874 | 2nd highest |
| Hokitika Airport | 981 | 145 | 1964 | 2nd highest |
| Cape Campbell | 202 | 164 | 1989 | Highest |
| Rangiora | 286 | 157 | 1965 | 2nd highest |
| Christchurch Airport | 223 | 167 | 1944 | 4th highest |
| Akaroa, Rue Lavaud | 351 | 214 | 1978 | Highest |
| Wanaka Airport | 289 | 186 | 1993 | 2nd highest 296 |
| Chatham Islands | 345 | 211 | 1951 | 2nd highest 380 |
Below average rainfall in some southern South Island areas
Rainfall was less than 80 percent of normal in Fiordland, south Westland and parts of Southland, and near average in Otago. Summer rainfall was extremely low to the far south of New Zealand.
Record low summer rainfall was recorded at:
| Location | Summer rainfall (mm) |
Percentage of normal | Year records began | Comments |
|---|---|---|---|---|
| Campbell Island | 234 | 72 | 1942 | 2nd lowest |
Very warm on the West Coast of the South Island
Cool in many eastern regions
It was very warm on the West Coast from Buller to Fiordland with mean temperatures about 1.0°C above normal. The summer was also warmer than normal in parts of Auckland, Waikato, Taranaki, Southern Lakes and Southland, with mean temperatures at least 0.5°C above normal. Cloudiness associated with onshore winds kept temperatures at least 0.5°C below normal in Hawke’s Bay, and in the east of the South Island from Marlborough to south Canterbury. Mean temperatures were near normal elsewhere.
Near or record high mean summer temperatures were recorded at:
| Location | Mean temperature | Departure (°C) | Records began | Comments |
|---|---|---|---|---|
| Puysegur Point | 14.4 | +1.2 | 1979 | 3rd highest |
Very cloudy in Wellington and Canterbury
Sunshine and solar radiation totals were below average over much of New Zealand, especially in Wellington and Canterbury where totals were less than 80 percent of normal. Taranaki, Westland and Southland measured near average sunshine hours.
Near or record low summer sunshine hours (as at 25 Feb) were recorded at:
| Location | Summer sunshine (hours) |
Percentage of normal | Year records began | Comments |
|---|---|---|---|---|
| Whakatane | 602 | 88 | 1957 | 2nd lowest |
| Taumarunui | 484 | 83 | 1948 | Lowest |
| Wellington, Kelburn | 553 | 81 | 1928 | 2nd lowest |
| Christchurch Airport | 520 | 82 | 1949 | 4th lowest |
Near or record low summer solar radiation was recorded at:
| Location | Summer Solar radiation (MJ m-2 / day) |
Percentage of average | Year records began | Comments |
|---|---|---|---|---|
| Kaikoura | 18.3 | 82 | 1969 | Lowest |
| Winchmore | 17.3 | 82 | 1960 | Lowest |
| Timaru Airport | 16.0 | 81 | 1984 | Lowest |
Highlights
Extreme temperatures
- The highest recorded air temperature for the summer was 34.4°C, at Timaru Airport, on 2 January. The highest January air temperature on record at Timaru Airport is 34.9°C.
- The lowest recorded air temperature for the summer was –1.6°C, at Ettrick, Otago on 16 February. This was Ettrick’s lowest February air temperature since measurements began in 1985.
Significant rainfall with flooding
- 2 December – High rainfall occurred throughout Northland. The Awanui River peaked 7 m above normal, blocking off parts of SH12 due to flooding.
- 3 January – Heavy rainfall (as much as 38 mm in an hour) deluged Westport, with some flood damage reported.
- 10 January – Thunderstorms over Wellington City resulted in torrential rainfall (about 40 mm in 30 minutes, and 52 mm in an hour) and flash floods in the city centre just after 7 pm on the 10th. This rainfall event had an average recurrence interval of well over 100 years. Thunderstorms, some with hail, and surface flooding also occurred over Wanganui, Manawatu, the central and eastern North Island, Buller and Nelson. Rainfall at Napier Airport totalled 29 mm in the hour to 9 pm on the 10th.
- 12–13 January – Houses were flooded and evacuated in Akaroa, the Kowhai Bridge was washed out, and the water supply was cut after heavy rainfall over the 12–13 January. The same weather system produced high rainfall, slips and surface flooding throughout Canterbury and the Kaikoura Coast (109 mm at Hanmer Forest, 106 mm at Kaikoura, 100 mm at Snowden for the 24 hours to 9 am on the 13th). SH1 was closed due to flooding in several places, with the Orari Bridge washed out south of Oamaru. High rainfall and flooding also occurred near Thames in the North Island, where the Tararu Stream overflowed its banks forcing 25 homes to be evacuated.
- 21 February – Whitianga, on the Coromandel, and Great Barrier Island were flooded by torrential rainfall. Whitianga Airport recorded 71.8 mm in the three hours to 9 am. Rainfall on Great Barrier Island totalled as massive 233.5 mm in the six hours to 9 am that morning.
Snow
- 30 December – Mt Ruapehu received an unseasonable dusting of snow.
Huge swells and rough seas
- 6 February – Huge 6–8-m swells were generated in Cook Strait by a severe southerly storm off the coast east of the North Island. These resulted in ferry cancellations and forced a southern coast road to be closed in Wellington. Three people had to be rescued from the sea. Heavy 5-m swells also affected Gisborne, where the Jody F Millenium – a log carrier – was grounded in rough conditions on a sand bar. Farther south, gales and 5-m swells generated by the storm resulted in the sinking of five small boats in Lyttelton Harbour.
- 13–14 February – Another depression resulted in gale-force southerlies with huge 6–8-m swells in Cook Strait. These resulted in fast-ferry cancellations.
Tornado
- A tornado passed over the Levin golf course just before 4 pm on 4 January, leaving a number of trees uprooted.
Lightning strikes and hailstorms
- 28 December – Hail lay 4 cm deep in parts of Rangiora following a convectional storm during the afternoon.
- 2 January – Hokitika Airport recorded 481 lightning flashes on 2 January, and 937 flashes for the first 4 days of the month.
- 4 January – A tourist was struck by lightning twice while tramping on the Ben Lomond track near Queenstown about 3 pm.
- 5 January – Thunderstorms, lightning, torrential rainfall and hail occurred over Christchurch during the afternoon, with hail lying up to 7.5 cm deep in some city areas.
- January – There was a thunderstorm somewhere in New Zealand on twenty-two days of the month.
For further information, please contact:
Dr Jim Salinger – Principal Scientist, Climate
NIWA National Climate Centre – Auckland
Phone +64 9 375 2053
[email protected]
Stuart Burgess – Climatologist
NIWA National Climate Centre – Wellington
Phone +64 4 386 0569
[email protected]
Geoff Baird – Communications Manager
Phone +64 4 386 0543
[email protected]
Acknowledgement of NIWA as the source is required.