La Niña, a climate phenomenon, has returned to New Zealand, bringing with it increased rainfall and warmer temperatures.

This natural occurrence happens when the ocean temperatures in the central and eastern Pacific Ocean become cooler than average.

La Niña events tend to bring more north-easterly winds, which result in moist and rainy conditions in the north-eastern parts of the North Island.

However, some areas like central Otago and South Canterbury may experience drought.

Warmer temperatures are also expected across the country, with a few regional and seasonal exceptions.

According to NIWA climate scientist, Dr. Gregor Macara, "La Niña events have a significant impact on New Zealand's climate. We can expect more rainfall in the north and east, and warmer temperatures overall."

La Niña occurs when the ocean water off the coast of South America to the central tropical Pacific cools to below average temperatures.

This cooling happens due to stronger than normal easterly trade winds, which brings cooler, deeper sea water to the surface.

The effects of La Niña on New Zealand's climate are varied.

While some areas will experience drought, others will receive much-needed rainfall.

Warmer temperatures will bring relief to some, but may also exacerbate drought conditions in other areas.

As Dr. Macara notes, "La Niña is an important reminder of the natural variability of our climate. While we can expect some changes, it's essential to remember that our climate is always changing."

La Niña is expected to last for several months, and its effects will be closely monitored by climate scientists and weather forecasters.

In the meantime, Coasties can expect a warmer and wetter winter than usual.