By Philip Duncan, WeatherWatch
Winter 2023 ends this week and what a strange winter it has been. It started off so incredibly mild and wet and has ended on a slightly drier note and cooler note.
Winter 2023 will very likely end warmer than average due to the exceptional warmth at the beginning. Even towards the end, here in August, there has still been a lack of really heavy frosts. I don’t even think we had any “severe” rated frosts this year – and if we did they were brief and isolated.
Average monthly and seasonal temperatures include both daytime and nighttime temperature – sometimes we can feel cold by day with cloud and cold winds, but the nights may be a few or several degrees milder – and that’s what helps make for a warmer-than-average month. It’s not always about having obviously warm days.
So let’s review where NZ stands as we head into September and spring 2023.
(((Pic: soil moisture)))
Soil moisture
Most regions are now at a much more acceptable rate of soil moisture. Yes, still muddy and squishy for some out there, but to be honest for the end of August that’s fairly normal now. Generally speaking the North Island is close to normal but, yes, still leaning slightly wetter than it should be for this time of year. Only slightly, however, which is better than being completely saturated. In the South Island it’s a similar story, although Canterbury and eastern Otago have pockets of much wetter-than-normal soil conditions following rain a month ago. Marlborough, Hawke’s Bay and the West Coast appear to have the most “normal” soil moisture conditions for late August.
Rainfall
August’s rainfall was more broken up and scattered, allowing a number of places to return to normal – or even below normal, which many desperately wanted and needed. The uptick in westerly driven weather means eastern areas in August had some of the driest weather, with the exception of eastern Otago and a couple of isolated parts of Canterbury. Hawke’s Bay, Gisborne and Western Bay of Plenty benefitted most from this drier set-up. The lower southern and southwestern corners of both main islands were the wettest – from Whanganui to Manawatū, Horowhenua to Kāpiti, Wellington and southern Wairarapa and then again around Fiordland, Southland and Stewart Island.
Sunshine
The more western driven set-up means western regions have been gloomier lately. The gloomiest places in August were the western coastal side of Northland, Whanganui, Taihape, Manawatū, Horowhenua, Kāpiti, Wairarapa, Wellington, South Westland, Southland and Otago. Sunniest and brightest regions were Bay of Plenty, Hawke’s Bay, Kaikōura, Marlborough and Nelson.
Highlights for the last week of winter:
• Monday kicks off with a colder southerly flow across all of NZ
• By Tuesday and Wednesday high pressure from the Tasman Sea moves in
• Colder nights again this week with the risk of frost inland
• High pressure slides off NZ on Thursday allowing for milder nor’westers
• September/Spring kicks off on Friday with rain or showers in the west and a milder airflow
