Weather: MetService looks back at 'wet and warm' 2022

By Mohammad Alafeshat for RNZ

With 2022 coming to an end, it's a good time to reflect back on the year of weather.

MetService has rounded up last year's weather as "wet and warm", with a clutch of significant storms and records broken.

Wet, warm and at times wild

Low pressure systems from the northern Tasman Sea were frequent around Aotearoa and brought a rise in both the temperature and amount of rain that fell.

MetService issued 53 Severe Weather Events last year and 182 Severe Weather Warnings.

At the beginning of February, West Coast communities were deluged by incredibly heavy rain, which hit Westland, Buller, and Taranaki. Within just 72 hours, 500 to 800mm of rain fell in parts of Westland.

Evacuations were ordered in Buller where a state of emergency was declared.

In the last week of March, heavy rain led to floods in and around Gisborne, with widespread damage across the region, and a state of emergency declared. Surging floodwaters being washed away a large chunk of riverbank leading onto the Tokomaru Bay bridge, isolating some communities for 10 days.

The abutment of a bridge at Tokomaru Bay was washed away in storms in March, leaving some communities isolated for 10 days.
The abutment of a bridge at Tokomaru Bay was washed away in storms in March, leaving some communities isolated for 10 days. Photo credit: Newshub.

Within weeks Cyclone Fili rolled in and MetService issued another Severe Weather Warning for Gisborne, and flooding and slips hit again.

In the middle of August heavy rain fell over much of New Zealand, creating problems from Northland to the the West Coast, with more flooding for Westland, and Buller.

That storm hit Marlborough and Nelson hard, and a state of emergency was declared in both areas. While slips and flooding also affected Wellington and Northland.

2022 by the numbers: what the weather stations showed

MetService said weather at the start of 2022 had been notably settled.

In January, prolonged hot and dry conditions spread from Auckland to Whanganui.

The Whanganui weather station received 0.2mm of ran, its driest month in more than 50 years of records.

The New Plymouth Airport weather station recorded 9.4mm of rain, which was the driest January there since records began in 1944.

In mid-February Cyclone Dovi rolled in and brought a record-breaking rainfall to Taupō, with the weather station clocking up 118.8mm in a day - the wettest 9am to 9am period there in almost 50 years.

Nearer the middle of the year temperatures dropped and thunderstorm activity increased.

A tornado blew through parts of Levin on 20 May.

The aftermath of the Levin tornado.
The aftermath of the Levin tornado. Photo credit: Newshub.

Thunderstorms were frequent from May into June and MetService said its lightning detection network picked up more than 111,000 strikes in the seven days up to 13 June.

MetService meteorologist Lewis Ferris said: "I can't remember being woken by lightning so much in the last five years living in Wellington."

2022: A winter for the record books

Last year was the wettest year of the last three decades.

Previously, the Christchurch Airport Station had not exceeded 200mm of rain in any single month, since it had been installed in 1943. But this July the station collected 309.8mm, or five times its average July rainfall.

Timaru and Blenheim also measured their record wettest months on record.

A weather station at Nelson Airport was another that sailed past its previous winter record of 570mm, which was set in 1970 - the station collected 701mm. It also measured a block of four days (17-20 August) when it exceeded its average measurement for an entire winter's rainfall.

Unsettled weather in November brought humid conditions and plenty of rain.

The Whangārei airport weather station recorded 367.0mm of rain, more than 100mm more than the previous wettest November recorded there. And Wellington had its wettest year since records began in 1928.