Dark skies and a trace of rain in Hawke's Bay on Tuesday was little sign of change in a month which could be one of the region's driest ever for the month of May.

Tuesday was the 11th mainly rainless day in a row, with no recording above a single millimetre since May 17 in Napier, Hastings or the Waipukurau area. Mahia had 3.2mm by late afternoon, MetService reported.

While rainfall has been significantly low in the region throughout the autumn, the region had been particularly dry from Hastings north, highlighted by a total of just 6.8mm at Hawke's Bay Airport, just over one-tenth of the station's May average of over 65mm, calculated from rainfall data over the last 30 years.

No rain had been recorded at the airport station in the last 11 days, and less than 190mm had been recorded in almost five weeks. Rainfall across the Heretaunga Plains and north to Kotemaori having in April had also been well below average.


Niwa reported the lowest monthly May rainfall in Napier in records dating back to 1870 was 2.6mm in 2007, when the rainfall at the airport station was 4.4mm.

Up to Monday night, there had been just over 15mm at Mahia, where the lowest May recording in data dating back to 1990 was 10mm, while this month's Hastings rainfall of 10.4mm compared with a 50-year-low of 3.8mm.

The heaviest rainfall at any of the four stations in the Hawke's Bay Today daily weather statistics was the 18.6mm on the Takapau Plains, still less than a quarter of the station's May average of 77mm.

MetService doubted, on latest predictions, whether any of the figures would as much as double by the end of the week. Although another front was due to bring a trace of rain overnight, the forecast was for fine weather over the next two days in the twin cities, and possible showers on the last day of the month on Friday, before a south to southwesterly change.

But while temperatures are forecast to drop, from recent highs of over 20C to 14-15C, there is also still almost no sign of rain in computer-generated forecasting out to late next week.