October 2002
Friday, 1 November 2002
The coldest October since 1982, with below average temperatures almost everywhere
Extremely sunny with below average rainfall in many regions
Wet in the east north of Gisborne and in the far south
October received more than the usual number of cold snaps, keeping temperatures well below normal in many areas. Ground frosts occurred with twice their normal frequency in inland parts of Bay of Plenty and Canterbury. The month was also exceptionally sunny compared to average, with many locations, throughout New Zealand, experiencing one of their sunniest October’s on record.
The normal spring warming was absent in October, due to the frequent southwesterlies and also frequent clear cold nights. The national average temperature of 11.0°C (1.1°C below normal) was the same as that of September 2002, and the lowest for October since 1982. Mean temperatures were at least 0.5 to 1.5°C below average throughout much of New Zealand. It was particularly cold, with temperatures more than 2.0°C below normal in parts of King Country, and inland Wanganui. In Canterbury, this was in significant contrast to September, which was very much warmer than normal.
Rainfall was below average throughout much of the North Island, the northern South Island, and parts of Central Otago. In central Marlborough rainfall was below average for the fourth consecutive month, with totals being 50 percent (half) or less of average. Rainfall was also 50 percent (half) or less than average in Bay of Plenty, and parts of the southern North Island. As a result, significant soil moisture deficits persisted in central Marlborough and now exist in northern and Central Otago and inland South Canterbury. In contrast, it was unsettled with above average rainfall in the east (north of Gisborne) and in coastal Southland.
October’s climate pattern was dominated by well below average pressures east of the Chatham Islands, producing more frequent cold southerlies over the eastern South Island and southwesterlies over the North Island.
Below average temperatures almost everywhere
Mean temperatures were at least 0.5°C below normal throughout much of New Zealand. They were at least 1.0°C below normal in the central and western North Island, south of Auckland and north of Wellington, including Gisborne, and in Canterbury, Otago and Westland. It was particularly cold, with temperatures between 1.5 and 2.5°C below normal in King Country and Wanganui.
Near or record low mean October temperatures were recorded at:
| Location | Mean temperature | Departure (°C) |
Records began | Comments |
|---|---|---|---|---|
| Henderson, Auckland | 13.1 | –1.9 | 1986 | 2nd lowest |
| Paeroa | 12.2 | –1.8 | 1947 | 2nd equal lowest |
| Rotorua Airport | 10.4 | –1.7 | 1964 | Equal lowest |
| Taupo Airport | 9.6 | –1.4 | 1976 | 2nd lowest |
| Taumarunui | 10.5 | –2.3 | 1947 | 2nd lowest |
| Chateau, Ruapehu | 4.5 | –2.1 | 1932 | 3rd equal lowest |
| Christchurch Airport | 9.9 | –2.0 | 1953 | 3rd lowest |
| Ettrick | 9.5 | –1.8 | 1985 | Lowest |
| Gore | 8.2 | –1.7 | 1971 | Lowest |
Overnight minima were particularly low, being about 1.5°C below normal in many locations. Near or record low October mean daily minimum temperatures were recorded at:
| Location | Mean daily minimum temperature | Departure (°C) |
Records began | Comments |
|---|---|---|---|---|
| Henderson, Auckland | 7.2 | –3.1 | 1986 | Lowest |
| Paeroa | 6.6 | –2.2 | 1947 | Well below average |
| Whakatane Airport | 5.6 | –2.6 | 1975 | 2nd lowest |
| Rotorua Airport | 5.1 | –2.5 | 1964 | Lowest |
| Taupo Airport | 4.2 | –2.1 | 1976 | 2nd equal lowest |
| Taumarunui | 4.7 | –2.7 | 1947 | Lowest |
| Whakatu | 5.9 | –2.2 | 1983 | 2nd lowest |
| Blenheim Airport | 4.3 | –2.4 | 1941 | Lowest |
| Hanmer Forest | 1.7 | –2.5 | 1906 | 3rd lowest |
| Christchurch Airport | 3.5 | –2.9 | 1953 | Lowest |
| Timaru Airport | 2.8 | –2.1 | 1962 | 2nd lowest |
Below average rainfall in many regions
Wet in the east north of Gisborne and in the far south
Rainfall was 75 percent or less of average throughout much of the North Island, the northern South Island, and parts of Central Otago. Rainfall was below average for the fourth consecutive month in central Marlborough, October totals being 50 percent or less of average. Rainfall was also 50 percent or less of average in Bay of Plenty, and parts of the southern North Island. Near record low October rainfall was recorded at:
| Location | October rainfall (mm) |
Percentage of normal |
Records began | Comments |
|---|---|---|---|---|
| Te Puke | 57 | 42 | 1973 | 3rd lowest |
| Palliser | 10 | 15 | 1987 | 3rd equal lowest |
| Wellington Airport | 22 | 27 | 1960 | 3rdlowest |
The month was unsettled with rainfall totals at least 120 percent of average in the east, north of Gisborne, and in coastal Southland.
Near record high October rainfall was recorded at:
| Location | October rainfall (mm) |
Percentage of normal |
Records began | Comments |
|---|---|---|---|---|
| Invercargill Airport | 163 | 180 | 1939 | 2nd highest |
| Chatham Islands | 116 | 207 | 1951 | 3rd highest |
Extremely sunny in most areas
Sunshine and solar radiation totals were 120 percent or more of average and exceptionally high for October at many locations throughout New Zealand.
Near or record high October sunshine was recorded at:
| Location | October sunshine (hours) |
Percentage of normal |
Records began | Comments |
|---|---|---|---|---|
| Kaitaia | 242 | 130 | 1951 | Highest |
| Auckland | 255 | 134 | 1909 | Highest |
| Taumarunui | *206 | 139 | 1947 | 2nd highest |
| New Plymouth | 254 | 134 | 1915 | Highest |
| Paraparaumu Airport | 257 | 143 | 1953 | Highest |
| Wellington, Kelburn | 260 | 133 | 1928 | Highest |
| Hokitika Airport | 227 | 141 | 1964 | 2nd highest |
| Nelson Airport | 283 | 131 | 1948 | 2nd highest |
| Blenheim | 282 | 125 | 3rd highest | |
| Christchurch | 272 | 133 | 1930 | Highest |
* to 9 a.m. on 31 October
Record high October solar radiation was recorded at:
| Location | October solar radiation, mean daily (MJ/m2) |
Percentage of normal |
Records began | Comments |
|---|---|---|---|---|
| Whitianga Airport | 20.5 | 126 | 1991 | Highest |
| Te Puke | 18.9 | 121 | 1987 | Highest |
Highlights
Extreme temperatures
- The lowest air temperature for the month was –7.4°C, recorded at The Chateau, Ruapheu on the 5th. The only lower October air temperature on record there is –8.3°C in 1945.
- The highest air temperature for the month was 26.1°C, recorded at Hanmer Forest on the 24th. The highest October air temperature on record at Hanmer Forest is 28.3°C.
Other extremely low October minimum air temperatures were recorded at:
| Location | Minimum air temperature |
Date | Records began | Comments |
|---|---|---|---|---|
| Lumsden | –4.1 | 4 Oct | 1987 | Lowest |
| Taupo Airport | –5.1 | 5 Oct | 1976 | Lowest |
| Motu | –5.8 | 5 Oct | 1991 | Lowest |
| Waiouru Military Camp | –6.3 | 5 Oct | 1966 | Lowest |
| Culverden | –5.0 | 15 Oct | 1983 | Lowest |
| Arthur’s Pass | –5.0 | 21 Oct | 1978 | Equal lowest |
Significant hailstorm
- Thunderstorms with large hail occurred in Canterbury on the 27th. Hailstones, some the size of golf balls, occurred in the Hornby area, damaging numerous strawberry plants. Other damages reported were denting of vehicles, and broken windows. Significant surface flooding resulted in Hornby shops after the event.
Tornados
- A tornado occurred at Taitapu, near Lincoln, southeast of Christchurch on the 28th, damaging trees in the area. Another tornado was sighted in Auckland on the 29th.
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.