CLIMATOLOGICAL TABLE—Summary of the Records of Temperature, Rainfall, and Sunshine for August 1956—continued

†Observations for 23 days.

LATE RETURNS

NOTE.—At stations where departures from normal have an asterisk, the temperature record has been maintained for less than ten years, the rainfall record for less than twenty years. Rainfall normals have been revised and now refer to the standard period 1921–50. Where observations are not available for the whole period, or where the site of the rain gauge has been changed, the normals are partly interpolated.

NOTES ON THE WEATHER FOR AUGUST 1956

General:

For most of the North Island August was the fifth successive month of unsettled weather, and in parts of the Auckland Province the wetness of the ground was adversely affecting the health of stock. In the South Island conditions were much drier and mainly favourable. In most districts of both Islands the weather proved reasonably good for lambing.

In the North Island the longest spell of fine sunny weather for four months occurred from the 18th to the 23rd.

Three small local tornadoes were reported, all from Taranaki. The first two occurred on the 24th and the third on the 26th.

Rainfall:

Rainfall was below normal over almost the whole of the South Island and also from Wairarapa to central Hawke’s Bay. In Marlborough it was only about a third of the average value. It was wetter than usual from Waikato and Hauraki northwards. A few places, including Auckland, had double the average.

It has been an unusually wet winter for western and northern districts of the North Island. For the three months, June to August, the total rainfall at Auckland was 26·56 in., which is the highest in 100 years of record. The previous wettest winter there was in 1916, with a rainfall of 24·13 in.

For most of this portion of the North Island the annual average rainfall was exceeded before the end of August; in parts of Northland it had already been exceeded before the end of July.

Many thunderstorms were reported on the 25th and 26th, especially in the Auckland Province.

Temperatures:

Over most of the Auckland Province mean temperatures were more than one degree above normal. Elsewhere the month was also mainly warmer than usual, but only by about half a degree.

There were two rather well defined cold spells. During the first, from the 4th to the 8th, the winds were southerly. This spell affected mainly the North Island, with snow on the high country. The second spell lasted from the 25th to the 29th, with south-westerly winds and snow on the high country of both Islands.

Sunshine:

Sunshine was mainly about normal. Marlborough and most of Southland were favoured with 20 to 30 hours more than usual, while Gisborne fell below normal by the same amount.

Weather Sequence:

On the first two days of the month a trough of low pressure moved eastward over the country and a depression formed to the north-west of Northland. Rain affected the North Island and coastal districts of the South Island. As the depression deepened and moved down the east coast on the 3rd and 4th, there was heavy rain over the Auckland Province, with some flooding. At the same time pressure rose in the south, and from the 4th to the 8th a cold south-easterly airstream covered the North Island. Cold, showery weather prevailed in eastern districts, with snow at times on the high country of the North Island. On the 8th rain extended to most of the Auckland and Taranaki Provinces and snow came down to unusually low levels as a small depression moved eastwards across the centre of the North Island.

On the 9th a depression crossed Northland, with further rain over the Auckland Province. For the next four days this depression moved slowly eastward, while another extensive depression remained stationary over the Central Tasman Sea; rain extended as far south as Canterbury. From the 14th to the 16th westerly conditions prevailed over most of the country, with pressure low to the south. However, yet another depression crossed Northland on the 16th and was still affecting the Auckland Province on the following day, although elsewhere the weather had cleared with the development of an anticyclone over the South Island.

From the 18th to the 23rd pressure remained high over the country as the anticyclone moved slowly eastward. The weather was sunny and mild apart from light rain at times in Northland, Gisborne, and the West Coast. In many districts, especially in the North Island, this was the longest spell of fine weather for four months.

A rapid deterioration occurred early on the 24th as a very deep depression passed to the south. The associated trough of low pressure crossed the country, bringing strong westerly to north-westerly