• Sunshine: Record cloudy for much of North Island and Nelson/Marlborough.
• Rainfall: Wettest summer on record for Takaka and Nelson. Very wet across the North Island, Otago and South Canterbury. Extremely dry over southwest of South Island.
• Temperatures: A cooler than average summer between Timaru and Gisborne, as well as for the Central Plateau and Bay of Plenty. Warmer than usual for the West Coast of the South Island and Fiordland.
• Soil Moisture: Above normal by the end of summer for Auckland, Bay of Plenty, Taranaki, Tasman, Otago and south Canterbury. Below normal for coastal Southland, Fiordland, Wairarapa and southern Hawkes Bay.
Summer (December 2011- February 2012) was characterised by more highs than usual near the Chatham Islands, and more lows than normal over the north Tasman Sea. This produced more northeasterly winds than usual over the country, consistent with the La Nina climate pattern present throughout the summer. December 2011 was notable for being extremely wet for the North Island and Nelson/Marlborough, with Takaka recording 392 mm on 14 December. In contrast, December was extremely dry over the west and south of the South Island. January was unusually cool, and February extremely cloudy, over much of the country.
It was an extremely cloudy summer across the North Island as well as in Nelson/Marlborough, with many records broken. Notably, it was the cloudiest summer on record for four of the six main centres (Auckland, Tauranga, Hamilton and Wellington). In contrast, it was sunny for the west and south of the South Island.
It was the wettest summer on record for Takaka and Nelson, with the summer rainfall totals about treble summer normal. Summer rainfall was also above normal or well above normal across most of the North Island, as well as in Otago and South Canterbury. In contrast, it was a rather dry summer over the west and south of the South Island. Soil moisture levels at the end of summer were above normal in Auckland, Bay of Plenty, Taranaki, Tasman, Otago and south Canterbury. In contrast, soils were drier than usual in coastal Southland, Fiordland, Wairarapa and southern Hawkes Bay by summer’s end.
Below average summer mean temperatures (between 0.5°C and 1.2°C below average) were experienced in Canterbury, the Kaikoura Coast, Wellington and the Wairarapa, Hawkes Bay, Gisborne, the Central Plateau, Taupo and Bay of Plenty. Above average summer mean temperatures (between 0.5°C and 1.2°C above average) were observed for Fiordland and the West Coast. Elsewhere, temperatures were close to average. The nation-wide average temperature in summer was 16.2°C (0.4°C below the 1971–2000 summer average), using NIWA’s seven-station temperature series which begins in 1909.
• The highest temperature was 31.7°C, observed at Lake Pukaki on 4 January.
• The lowest temperature was -0.9°C, at Ranfurly on 3 January.
• The highest 1-day rainfall experienced was 392 mm at Takaka on 14 December.
• The highest gust recorded was 185 km/hr at Rock and Pillar Range, Central Otago, on 31 January.
• Of the six main centres in summer 2011/2012, Tauranga was the warmest and sunniest, Hamilton the wettest and cloudiest, Christchurch the driest, and Dunedin the coolest.