with John Maunder
Climate extremes in New Zealand, since instrumental records became available in the 1850's, show a range from the highest temperature of 42.4 degrees Celsius recorded in Rangiora on February 7, 1973, to the most intense rainfall in 10 minutes – 34 mm which occurred in Tauranga on April 17, 1948.
The National Institute of Water and Atmospheric Research (NIWA) updates the weather extremes recorded in New Zealand since observations were officially recorded in the 1850's.
The current extremes up to December 2016 include the following:
Wettest: A record 34 mm occurred in 10 minutes in Tauranga on April 17, 1948. In one hour, 134 mm was recorded at Cropp at Waterfall in the Hokitika Catchment. This site also has the NZ record for the highest 24 hours' fall of 758 mm on December 27-28, 1989, and the highest 48-hour-fall of 1049 mm on December 11-13, 1995. It also had the highest fall in a calendar month of 2827 mm in December 1995, and the highest fall in a calendar year of 16,617 mm in 1998.
Driest: Only 9 mm of rain fell at Cape Campbell, Marlborough, from January to March 2001; the driest three months ever recorded in New Zealand. The driest six months was also recorded at Cape Campbell, from November 2000 to April 2001 when only 52 mm of rain was recorded. The driest 12 months was in Alexandra from November 1963 to October 1964, when only 167 mm was recorded. The longest period without rain is 71 days, which occurred in Wai-iti, Marlborough, from February 8, 1939.
Warmest: Until 1973, the highest temperatures officially recorded in New Zealand was 101.3 degrees Fahrenheit (38.4 degrees Celsius) at Ashburton and Darfield on January 19, 1956. However, under extreme northwesterly conditions on February 7, 1973, there was a recorded 42.4 degrees Celsius (108.3 degrees Fahrenheit) at Rangiora. A temperature of 42.3 degree Celsius was also recorded on this day at Jordan, Marlborough.
Coldest: The coldest air temperature ever recorded was minus 25.6 degrees Celsius in Eweburn, Ranfurly, on July 17, 1903. The lowest grass temperature is minus 21.6 degrees Celsius recorded at Lake Tekapo on August 4, 1938.
Sunniest: Nelson, Takaka, Riwaka, Blenheim, Lake Tekapo, Tauranga and Whakatane often appear in the list of very sunny places in New Zealand – but officially Richmond has recorded the most sunshine in any one year with 2840 hours in 2016. In the North Island, Whakatane recorded 2792 hours of sunshine in 2012.
In contrast, only 1333 hours of sunshine was recorded in Invercargill in 1983. For one month, the sunniest locations Nelson with 336 hours in December 1934, and New Plymouth also recording 336 hours in January 2015; and the least sunny location is Taumaranui, with only 27 hours in June 2002.
Wind Gust: The highest wind gusts recorded in New Zealand were 250 km/h at Mt John, Canterbury, on April 17, 1970 and 248 km/h at Hawkins Hill, Wellington, on November 6, 1959, and July 4, 1962.
For further information see: https://sites.google.com/site/theweatherclimateeye/