March 1991: It was much drier than average, with record low rainfall in Westland. It was also very sunny, especially in Northland and Taranaki, with less than the usual amount of wind over the whole of New Zealand.

These conditions were caused by an extremely unusual pattern of almost stationary anticyclones to the east of the South Island. These gave mostly dry settled weather for much of the month, with easterly winds over the northern part of the North Island and light winds or light northeasterlies over the South Island. March was the least windy month at Invercargill since 1962, with one day with wind gusts above 63kph (average 9), and the least windy at Wellington since records began in 1967, where there were 5 such days (average 16).

[This was the anomalous month of 1991. A strongly developing El Nino gave central New Zealand in 1991 the lowest overall MSLPs in at least 80 years, bar 1968, with Westland having a very wet and cloudy year].

Rainfall: Rainfall was 5 to 20% of average in Westland, and 25% of average in Fiordland. Hardly any rain occurred in Westland (1mm at Hokitika) until the 22nd.
Record low March rainfalls occurred at Hokitika (39mm), Franz Josef (37mm) and Haast (84mm). It was also very dry (20-40% of average) in Northland, Bay of Plenty, Rotorua, the Central Plateau, Wellington, Buller and coastal areas of South Canterbury. Rainfall was 40-75% of average in most other regions, except for Auckland, Gisborne, Taranaki and the Mackenzie Basin where totals were up to 20% above average.

High rainfall was recorded over the Coromandel Peninsula on the 26th, with 89mm at Whitianga.

Temperatures: Mean temperatures over much of the North Island were at least 0.5C below average, and 1.0C below average in Waikato. They were 0.5C or more above average in the southern half of the South Island, and 1.0C above average in Central Otago and Southland.

Sunshine: Sunshine hours were up to 40% above average in Northland, 30 to 35% above in Taranaki and Marlborough, and at least 20% above average in Auckland, Nelson and coastal South Canterbury and Otago. Record high values were recorded at Kaitaia (253 hrs, records from 1951) and New Plymouth (261 hours, records from 1935). The persistent easterlies brought cloudier than usual weather to Gisborne and (to a lesser extent) Hawkes Bay.

[Some totals: Kaitaia 253, Tauranga 226, Te Teko 209, Rotorua 199, Taupo 183, Mangere 217, New Plymouth 261, Masterton 181, Dannevirke 160, Martinborough 195, Gisborne 168, Napier 191, Wairoa 173, Paraparaumu 236, Ohakea 211, Palmerston North 198, Wellington 221, Stratford 221, Wanganui 218, Takaka 225, Westport 179, Arapito 193, Hokitika 165, Greymouth 170, Nelson 251, Blenheim 227, Mt Cook 160, Christchurch 187, Timaru 156, Palmerston 157, Dunedin Aero 169, Dunedin 149, Queenstown 181, Cromwell 219, Alexandra 215, Invercargill 151, Chatham Is 119].


Sources: NZ Met. Misc. pub. 107 (Climatological table, NZ Gazette) and NZ Met. Misc. pub. 109 (Meteorological Observations) - additional comments by the poster.