Did all that rain end the big dry?

The cloud and rain over Northern Hawke's Bay has ex-tropical Cyclone Pam passed by this week. Time will tell whether it was enough. Photo / Duncan Brown

This week's rain comes with mixed blessings for Hawke's Bay farmers, some of whom will be asking what's next?

While many areas had rainfalls of 60mm or more, courtesy of ex-tropical cyclone, Pam, much of Hawke's Bay has still had below average rainfall for the late summer months.

According to MetService figures yesterday, while Napier was ahead of its March average, things were not nearly as rosy in Central Hawke's Bay.

Rainfall for the month at the Takapau Plains recording station is about three-quarters of the average to date and, in northern Hawke's Bay, where Mahia rainfall is about 86 per cent. Conversely, about 25 per cent of the region's rainfall comes in the two months of June and July.

The rain was most beneficial in northern Hawke's Bay, which had been treated kindly by the elements in the early summer but was getting "pretty dry", according to Hamish Bayly, who has farming interests in northern Hawke's Bay and the Gisborne region.

The deteriorating situation prior to the rain was highlighted by the cancellation of the Wairoa Collie Club's annual sheep dog trials, but Hawke's Bay Regional Council's talk of "drought" in a media release on Friday seemed to be just what the doctor ordered - the rain followed.

"In the past 10 years we have experienced five years of significantly stressful summer periods or drought," said council chairman Fenton Wilson.

"This has a real impact on the community of Hawke's Bay as a whole. It's not just the growers but all the business, services and workers beyond the farm gate that are affected by a downturn in farm incomes. Quite simply we need rain and soon."

HBRC estimates last week were that the region needed at least 75mm of rain over an extended period "to get things going again - soil moisture, river flows and pre-winter crop and pasture growth".

The expected rain was not anticipated to deliver sufficient moisture to change the situation greatly, the HBRC said, but more rain is forecast, particularly from Hastings south, next week.

Dry spells are common in Hawke's Bay during late spring, summer and early autumn.

According to Niwa figures, there is an average of 3.5 such periods each year in Napier, 2.6 in Ongaonga, and 1.7 in Wairoa.

The average duration of a dry spell is about 19 days.

The longest dry spell between three key sites in Hawke's Bay over the last 30 years was 40 days, in Napier during April-May, 1986.

There were 20 consecutive days without any rain, barely a trace, and then another extended spell without any significant rain.

The longest at Ongaonga was also 40 days. This has happened twice, in May-June, 2007, and in February-March two years ago, the last declared drought in Hawke's Bay.

In Wairoa, the longest recent dry spell was 27 days, with less than 1mm of rainfall recorded in November 1994.