December 1972:  Pressures were unusually low over New Zealand in December, and the weather was cool and windy. Over the northern half of the North Island, good growth was reported, but elsewhere conditions were too dry.

Rainfall: Rainfall was below normal over the greater part of the South Island, mainly by 25%, and also over the southern half of the North Island, mainly by 50%. Blenheim received only 13mm and Nelson 17mm. On the other hand, rainfall was more than double the normal value in northern Hawkes Bay and southern Gisborne. In this area some particularly heavy rain was recorded on the 1st and 2nd, with as much as 320mm over the 2 days.

223mm rainfall at Frasertown (Wairoa), 24mm at Napier, 6mm at Vernon Lagoon (near Blenheim).

Temperatures:  Temperatures were mainly below normal by 1C. Highest departures were recorded in parts of Canterbury and in Central Otago. The coldest part of the month was the first week and also the 13th and 14th. Conditions were particularly wintry in eastern districts on the 1st and 2nd. In Auckland and most of Northland temperatures were normal.

32.0C maximum at Hastings on the 31st, -3.4C minimum at Molesworth on the 3rd.

Sunshine:  Sunshine was close to normal over the greater part of the country, especially the South Island. However, it was up to 45 hours below normal in Northland and Auckland and also in south Taranaki, Wanganui and Manawatu.

[Some totals:  Kaitaia 176, Kerikeri 177, Whangarei 183, Leigh 193, Auckland 180, Tauranga 228, Whakatane 242, Taupo 229, Opotiki 215, Auckland Aero 199, Hamilton 193, New Plymouth Aero 202, Masterton 198, Gisborne 242, Napier 236, Wairoa 233, Paraparaumu 193, Ohakea 200, Kairanga 196, Palmerston North 143, Levin 188, Wellington 222, Stratford 190, Ohakune 163, Wanganui 186, Takaka 248, Westport 198, Hokitika 197, Greymouth 175, Haast 197, Riwaka 266, Nelson 244, Blenheim 268, Grassmere 233, Kaikoura 206, Mt Cook 173, Mt John 245, Methven 195, Christchurch 211, Tekapo 232, Timaru 193, Waimate 195, Omarama 193, Palmerston 178, Dunedin Aero 163, Dunedin 162, Oamaru 192, Queenstown 229, Alexandra 214, Invercargill 184, Raoul Is 259, Campbell Is 109, Chatham Is 143].

Sources: NZ Met. Misc. pub. 107 (Climatological table, NZ Gazette) and NZ Met. Misc. pub. 109 (Meteorological Observations).

maybe it was during a strong El Nino event at the time.