The big snow of 1976: When New Zealand ground to a halt

Friday, 19 June 2026

A vehicle is towed out of snow in the Wellington region in 1976.

Paul Gorman is a senior science writer.

ANALYSIS: Snow seems to have become an increasingly scarce commodity in recent years, particularly when it comes to significant amounts falling to low levels.

We haven’t stopped getting the icy southerly airstreams or snowy systems that we used to.

Snowfall across Marlborough’s Wairau Valley in the winter of 1976.

In fact, weather features that bring low and driving snow are becoming supercharged due to more energy from a warmer atmosphere and can bring even heavier precipitation.

It’s just that, as climate change has steadily lifted average temperatures higher, it’s taken the freezing level up too. That means a marginally snowy system that may have brought heavy snow to nearly sea-level a few decades ago may now only bring heavy sleet or rain.

Of course, if an Antarctic air mass is frigid enough and by no means marginal, then snow will still fall all the way down to sea-level in New Zealand.

The synoptic chart, with high pressure near Tasmania and low pressure over the Chathams dragging icy southerlies over the country.

Fifty years ago this weekend, we were on the cusp of a “once in a generation”, several day nationwide snowstorm.

Much of the South Island, other than the West Coast and parts of the north, ended up many centimetres deep in snow that hung around for days. It snowed in Wellington – heavily. It snowed in Auckland – lightly.

The bitter southerly, originating in Antarctica at about the 70°S latitude, hit the far south on the afternoon of the 20th, a Sunday. By that evening, Dunedin was at a standstill, with 15cm on the hills and most roads blocked.

The tongue of frigid air bringing almost nationwide snow is clear in this Earth Sciences NZ reanalysis of the atmospheric temperature on June 21, 1976.

In Christchurch, sleet and rain turned to steady snow about 9pm. Your intrepid columnist recalls his dad waking him up to look outside at the flakes falling heavily against the streetlights.

Snow kept falling in frequent heavy flurries throughout Monday, particularly overnight and into Tuesday too, with 10cm or more settled across the city flats and more on the Port Hills.

There were two days off school.

Snow covers a car at the summit of the Rimutakas, near Wellington, in 1976.

Weather historian and retired MetService meteorologist Erick Brenstrum was a young forecaster at Christchurch Airport and recalls that Monday evening.

“Very impressive. I remember driving home slowly from work at 9pm carefully keeping the car’s wheels in the tracks left by other vehicles. There were no other cars on the road by this time.

“Years later, I saw a photo of the car park in Kelburn where the snow was deep enough for cars to leave tracks.”

Mt Hutt ski field opened in May 1976 with about 90cm of snow covering the field.

The snow reached Wellington before dawn on Monday. Flurries fell to harbour level and at the airport, while heavy snow lay between 5 and 10cm thick on the hills, isolating residents in Karori, Wilton, Kelburn, Brooklyn, Ngaio and Khandallah and closing roads.

That afternoon, sleet showers and then snow flurries moved across parts of Auckland, falling at the airport and in elevated locations like Mt Albert. Snow was also falling in Taranaki, with 5cm in Stratford, and even in Northland, with a skiff settling on the Tutamoe Plateau north of Dargaville.

Over the course of two days, it became the worst and most widespread snowstorm since July 1939.

Fortunately, stock losses were minor. But new national records for electricity consumption were set and roads across the South Island were blocked with snow for days, with drifts up to 1.5m deep in North Canterbury. Inter-island ferries battled through huge southerly swells in Cook Strait.

So, what caused it?

One of the tools forecasters use to predict snow is the “thickness” of the atmosphere between two pressure heights (1000 and 500 hectopascals), given cold air is denser than warm air and will have lower thickness.

Reanalysis by Earth Sciences New Zealand shows on June 21, 1976, there was a tongue of polar air across the country, with its lowest thickness about 5220 geopotential metres (gpm). Snow will often fall to near sea-level with 1000-500hPa thickness of 5250gpm.

Just how cold it was can also be seen in the upper-air temperatures. At the 850hPa or 1500m level – chosen for forecasting as an accurate marker of changes in temperature because it sits above the chaotic “noise” of layers closer to the surface – it was about -8°C across parts of the South Island that morning.

Such very cold temperatures are a really good signal of sea-level snow. The environmental lapse rate of moist air is a drop of about 0.5°C per 100m of altitude, which means on the 21st the temperature at sea-level was just below freezing.

New Zealand has had three standout snowstorms which affected the entire country in the past century – July 1939, June 1976 and August 2011. While there’s always a chance it could happen again this winter, the warming atmosphere is going to keep on making it just that bit more difficult every year.