UPDATE

Warmest

1. 1998 had 19.61 which is 2.39 above average

2. 2016 had 19.46 which is 2.24 above average

3. 1938 had 18.94 which is 1.72 above average

4. 1990 had 18.78 which is 1.56 above average

5. 2023 had 18.56 which is 1.34 above average

6. 2005 had 18.55 which is 1.33 above average

7. 1974 had 18.52 which is 1.30 above average

8. 1966 had 18.46 which is 1.24 above average

9. 1971 had 18.45 which is 1.23 above average

10. 1935 had 18.45 which is 1.23 above average

Coolest

1. 1937 had 14.28 which is 2.94 below average

2. 1976 had 14.30 which is 2.92 below average

3. 1912 had 14.34 which is 2.88 below average

4. 1931 had 14.50 which is 2.72 below average

5. 1926 had 14.73 which is 2.49 below average

6. 1923 had 14.94 which is 2.28 below average

7. 1940 had 15.22 which is 2.00 below average

8. 1915 had 15.27 which is 1.95 below average

9. 1993 had 15.50 which is 1.72 below average

10. 1942 had 15.57 which is 1.65 below average

1958 was actaully warmer than normal, according to the report. But it followed some cool months.

Just as a reminder - here is part of the report for February 1958: (whole report in the relevant section):

"February 1958: A wet month, with extensive flooding. It was also cloudy, warm and humid. Over the greater part of the country the rain was welcomed after dry weather in January, and stocks and crops benefited. In some inland districts of Canterbury and Otago conditions were considered too wet for sheep.

Rainfall: Rainfall was from two to four times the normal value in the Auckland province (except Gisborne) and also in most western and inland areas of the South Island south of Hokitika. From Kaitaia northward and in a small area around Hamilton totals exceed four times the average. In these areas it was by far the wettest February on record; and in Hamilton it was the wettest of any month in over 50 years of observation, Ruakura receiving 12.75”. [Te Paki station,Te Hapua in the far north had 17.28”, almost 5 times the average.]

Heavy rain in the Auckland province on the 23rd and 24rd caused unusually widespread flooding, affecting especially the King Country, the Kaitaia district, and the Waikato, Tongariro, Wanganui and Rangitikei rivers. The Auckland-Wellington railway line and main roads were closed for many days. Among the heaviest falls over the two days were 12” at Rangipo and 9.7” at Glenbrook, Otorohanga. In the south, Milford Sound received a total of 69”, its highest monthly rainfall and not far short of the New Zealand record for a month of 73” at Homer Tunnel in February 1940 [since surpassed by a large margin with the advent of higher altitude rainfall sites]. The fall of 20.5” on the 12th at Milford was also one of the highest ever recorded in the country. The heavy rain extended to the Lakes district, and the Clutha River was in flood from about the 13th of the month.

Temperatures: Temperatures had been cooler than normal for the previous 4 months, but February was warmer than normal throughout the country. Departures were mainly 3F-5F, but were somewhat lower in eastern districts of the South Island.

Sunshine: Sunshine was more than an hour per day below normal, except in eastern districts of the North Island and on the Southland Plain. Over a considerable part of the South Island, from Central Otago northward, it was the cloudiest February on record, and in some places such as Nelson also by far the cloudiest summer month."

Property damage bill would have been significant. I once saw an old NZ film unit newsreel from their archive, covering the visit of HM Queen Mother that month. They showed a short sequence of a boat race in the Wanganui river where the muddied riverbanks were very obvious - in their usual gung-ho way this was brushed off … the price of this warm month in anotherwise cool summer (and the worst on record for a significant area, considering the period October to March overall) was pretty high.