Weather: Warmer than average temperatures, irregular rainfall approaching winter

Winter is around the corner, but forecasters predict higher than average temperatures for most of New Zealand over the next three months.

Irregular rainfall around the country is also on the horizon, with parts of the country drier than usual and the potential for more floods between dry spells.

The seasonal climate outlook for May–July, released yesterday by the National Institute of Water and Atmospheric Research (Niwa), shows higher-than-average temperatures are very likely in the North Island and west of the South Island.

Temperatures are also likely to be average or warmer than average in the north and east of the South Island.

The outlook said "marine heatwave conditions" would likely delay the seasonal transition to cooler temperatures, frosts and snowfall.

It also noted fewer southerly winds could reduce chances of snowfall.

🔮 May-July climate outlook — https://t.co/XabX7ghKOa

🌤️ Dryness still a factor for some: longer dry spells with heavy rainfall occasionally mixed in

🌡️ Leaning warmer: more northerlies from La Niña, marine heatwave continues

🌬️ Less southerlies: could reduce snow chances pic.twitter.com/xgvhGLDIbr

— NIWA Weather (@NiwaWeather) April 29, 2022

The northern part of the country is the most likely to get warm weather in the coming months, with a 70 per cent chance of above-average temperatures in Auckland, Northland, Waikato and Bay of Plenty.

The rest of the country has a 50–65 per cent chance of warmer than average temperatures.

Niwa also forecasts rain around the country could continue to be "irregular", with longer dry spells interspersed with heavy rainfall and possibly flooding.

The north and east of the North Island are most likely to get above-average rainfall – with a 35 per cent chance - while the rest of New Zealand can expect rainfall to be normal or below normal.

The lower North Island, as well as the east and north of the South Island, have a 35 per cent chance of below-average rainfall.

Throughout April, coastal water temperatures around New Zealand had been above average, with anomaly values increasing in nearly all regions of the country.

The Southern Oscillation index, which measures changes in atmospheric pressures across the Pacific, was the also the third highest April in nearly 150 years.

This shows the influence of the weather pattern La Niña on global atmospheric levels, the outlook said.