Looks like 0.3C below 1951-80 normal average Tmax at Aero and 0.1C below at Gardens. But Tmeans were up about 0.6C and Jan 1973 was quite warm for NZ overall, and very dry for most. February more dramatic - here's part of the monthly summary (I have added in a few numbers from the stats. section):NZstorm wrote: ↑Sun 10/12/2017 07:43 There were some high maximums in Christchurch in the days leading up to 7 feb 1973.
3rd 30C, 4th 33C, 5th 33C, 6th 28C.
The 43C occurred in conjunction with a front because on the 8th the max was only 18C.
January 1973 was a below average month for max temps at Christchurch. So looks like it was just a synoptic warm event rather than any seasonal situation.
February 1973: Pressures were unusually high over New Zealand, and this was one of the driest months on record, besides being sunny and warm with some exceptionally high temperatures. January had also been dry, and the greater part of the country made little pasture growth. Drought conditions became fairly general.
Rainfall: For the country as a whole rainfall was only 25% of the normal value. Negligible amounts of less than 10% of the normal were recorded over about half the North Island, mainly in western districts; also in many inland districts of the South Island, in Nelson and in Marlborough, and in coastal North Otago. [Stratford Mountain House had 4mm, barely 1% of average]. In the North Island this month was not as dry as January 1908.
The only areas with rainfall about normal were Fiordland, with Stewart Island and parts of South Westland, where nearly all the rain fell in the first 10 days; and also some of Gisborne and northern Hawkes Bay. Sites with nil rainfall included Manaia, Motueka (Riwaka), Appleby and Blenheim Aero. Milford Sound reached its average with 595mm, nearly all of it falling in the first week.
Temperatures: Temperatures were mainly above normal by up to 3C, with highest departures over inland South Island districts and the Canterbury Plains. It was very warm east of the ranges from the 4th to the 7th. Until this time the record high temperature for New Zealand was 38.4C at Ashburton, 19/1/1956. However, on the 7th most stations in Canterbury exceeded this value, and a new record of 42C was established at Christchurch, Rangiora and Jordan (Awatere valley). New station records were also established in parts of Marlborough, Nelson, Hawkes Bay and Gisborne.
[Some maxima: 37.7 (Oamaru Aero), 39.0 (Waimate), 39.8 (Timaru Aero), 40.4 (Lincoln), 41.6 (Christchurch Gardens), 42.4 (Rangiora), 41.3 (Ashburton), 37.1 (Hanmer), 42.3 (Jordan), 37.8 (Blenheim Aero), 36.3 (Nelson Aero), 39.2 (Ruatoria – North Island record).]