Heretaunga Plains rainfall one-fifth monthly December average

Following a dry December and rain last Friday, the week is set to be mainly fine aside from some showers on Tuesday. Photo / Ian Cooper

The extremes of the weather in Hawke's Bay have been highlighted in new rainfall figures for the Napier-Hastings area at the end of 2020.

According to Hawke's Bay Regional Council's monthly rainfall reports, rainfall on the Heretaunga Plains in November was more than three times the 30-year average for the month, while December's rain was barely one-fifth of the December average.

The November 9 Napier flood was part of a sharp reversal from the numbers during the Hawke's Bay drought earlier in the year.

It contributed to the average across six recording stations across the plains, being 3.28 times the November average - the HBRC rooftop gauge in central Napier itself having almost six times its November average in just one day.

By contrast, rainfall across the plains and Napier in December was just 22 per cent of the December average.

Rainfall across the region has not exceeded the 30-year average for two months in a row since December 2018-January 2019, and has been above average just six of the last 25 months.

HBRC principal scientist Dr Kathleen Kozyniak said figures for the plains in December were "looking a lot worse until we had some manky days around Christmas and New Year's Eve".

"Northern Hawke's Bay and Waikaremoana are keeping to the La Nina plan – receiving near normal December rainfall," she said.

"The other areas were fairly woeful, especially the Heretaunga Plains, which managed only 22 per cent of the average December total."

Federated Farmers Hawke's Bay president Jim Galloway said December was "very, very dry" but the rainfall in November had helped with feed growth going into summer.

"We've had below-average rainfall except for a couple of months in the last 18 months, two years now.

"It's a cumulative effect that doesn't take much to dry out, if you're okay on top it can try pretty fast if you haven't had decent wetting rain.

"So, everyone was very nervous up until that November rain."

A dry summer is expected, and it's "not too much of a worry" at this stage, but if there is no autumn rain in March or April at the latest, "that's when it becomes an issue".

He said learning from last year's drought, it was best to plan and make decisions early.

Yummy Fruit general manager Paul Paynter said the November rain had brought rainfall numbers up "in a big hurry".

The dry December did not have much of an impact as soils have "great" water holding ability and drainage.

The bigger concern is that having too many wet days in the coming months - stopping days of picking - combined with the labour shortage would be something the industry "can't afford", he said.

After thunderstorms on Friday predominantly affecting Central Hawke's Bay, the week is shaping up to be fine apart from a few showers easing by the evening on Tuesday.

Temperatures throughout the region will be in the low 20s for the week until Saturday, which is forecast to be in the mid-upper 20s in various parts of Hawke's Bay.