31 JULY

THE NEW ZEALAND GAZETTE

CLIMATOLOGICAL TABLE—Summary of the Records of Temperature, Rainfall, and Sunshine for June 1975—continued

The “normal” refers to the present site of the instruments. Standard periods for normals are: Temperature 1941–70, Rainfall 1941–70 Sunshine 1941–70. No normals are available for stations with only short records.

*Indicates that the sunshine recorder is not located at the station but is in the near vicinity.

A rain day is a day with rainfall equal to or greater than 0.1 mm.

Where the extremes of temperature and rainfall have occurred more than once during the month, the date of the first occurrence is given.

NOTES ON THE WEATHER FOR JUNE 1975

General—June was marked by a greater frequency of south-easterly winds than usual, and it was the first month since August 1974 with temperatures colder than normal. Frosts cut back pasture growth but most stock appeared to be wintering well.

Rainfall—Rainfall was above normal over the greater part of the North Island and also over most eastern districts of the South Island from Timaru northward. The main areas where the surplus amounted to more than 50 percent were the Canterbury Plains with Banks Peninsula and coastal North Canterbury, districts around Cook Strait, and eastern Northland from about Whangarei to Whangaroa.

Rainfall was more than 25 percent below normal in Fiordland, most of Westland, Otago, and Southland, and parts of South Canterbury, Nelson, and Manawatu.

In many districts, including Auckland, Wellington, and most of Canterbury, well over half the rain fell in the 3 days from the 13th to the 15th, during the passage of a depression across the North Island. In southern and eastern districts of Banks Peninsula the total rainfall for these 3 days was unusually high, up to 340 mm. Many areas throughout the country reported local flooding, and at the same time, gales.

Temperatures—Temperatures were mainly below normal by about ½°C. The last week was particularly cold and frosty. At Twizel in the Mackenzie Country the minimum air temperature fell below freezing every day after the 7th. On the 17th, 24th, and 25th the air temperature remained below freezing all day. Considerable snow fell in this and neighbouring areas from the 14th to the 16th.

Parts of inland Canterbury reported the ground frozen to a depth of 10 cm by the end of the month.

Sunshine—Sunshine was mainly close to normal or above it. Parts of Canterbury, Central Otago, and inland Southland were favoured with a surplus of 15–30 hours.

Weather Sequence—At the beginning of June pressures were high over the Tasman Sea and the South Island and also over the Chatham Islands, while a complex depression was centred to the east of the North Island. Rain was reported mainly in eastern districts from Napier northward. On the following 2 days, as the depression moved away eastward another shallow depression approached Northland. Showers were reported over most of the North Island and also in the far south of the South Island.

The weather on the West Coast deteriorated on the 4th and 5th with the approach of a trough of low pressure associated with a depression far to the south-west. Some rain was also reported in Nelson and parts of the North Island, with temperatures becoming milder. This trough crossed New Zealand on the following 2 days,

with considerable rain west of the ranges in both islands and some lighter falls in the east. On the 8th some further rain was reported in eastern districts of the North Island with a general change to cold southerlies. For the next 2 days south-westerlies prevailed, and a few showers were still reported, especially in Fiordland and on the Southland coast. On the 11th an anticyclone centred over the North Island covered the country, with generally settled weather.

On the following day depressions were centred over the North Tasman Sea and far to the south, with an assassociated trough of low pressure moving on to the country from the west. Rain was reported on the West Coast and the Southland coast. During the 13th and 14th the northern depression moved on to the North Island while the trough of low pressure moved slowly eastward over the country. Rain became general over the North Island and part of the South Island, with many considerable falls. Local flooding was reported in some areas and gales were widespread. Snow fell in the MacKenzie Country of Canterbury. By the 15th the depression had deepened and was centred east of Hawke’s Bay. Cold southerlies prevailed over the South Island, and further rain was reported over the greater part of the country. In most districts these 3 days were by far the wettest of the month. On the following day the depression was centred near the Chathams, while an anticyclone was centred near Melbourne. Cold southerlies covered the country with some further showers, mainly in the east.

From the 17th to the 19th the anticyclone over Victoria advanced slowly eastward, and the winds over New Zealand became south-westerly to westerly. A few showers were still reported, especially in Fiordland and on the Southland coast. Temperatures became warmer in the east. During the following 2 days a trough of low pressure associated with a depression to the south, crossed the country. Rain affected mainly western and southern districts of the South Island.

By the 22nd the anticyclone was centred near Campbell Island and a depression was centred off the coast of New South Wales, with a trough of low pressure extending from there close to Northland and away to the east. During the next 2 days the depression moved eastward and became complex, one centre crossing the North Island. At first rain affected mainly Northland and Auckland but later it spread over the whole of the North Island with some considerable falls, especially in Waikato, Bay of Plenty, Gisborne, and parts of Hawke’s Bay. On the 25th the trough extended to the north-east of the North Island and rain was reported mainly in Northland and Gisborne. During the last 5 days of the month the anticyclone moved on to the South Island. Pressures were still low to the north-east and some further showers were reported at first east of the North Island ranges. Otherwise the weather was settled. The whole period from the 22nd to the 30th was cold and very frosty.

J. F. DE LISLE, Director.

(N.Z. Met. S. Pub. 107)