Climate

The NINO3.4 Index anomaly (in the central equatorial Pacific) over the last month was -0.68˚C, near the La Niña threshold. The monthly Southern Oscillation Index (SOI) was +1.3 and the three-month average SOI was +1.0, both in the La Niña range.

2021: New Zealand’s warmest year on record

New Zealand’s 4th-warmest December on record

La Niña conditions strengthened in the equatorial Pacific during December. It is expected to continue to be a key climate driver for Aotearoa New Zealand over the next three months, with an 80% chance for its continuation.

Forecasting sea surface temperatures several months in advance is challenging. To give us insights into what might happen around Aotearoa New Zealand in the months to come, NIWA scientists have combined predictions from eight different climate models from institutes around the world.

The NINO3.4 Index anomaly (in the central Pacific) during November (through the 28th) was -0.59˚C and the Southern Oscillation Index (SOI) was +1.1, both near the La Niña threshold. The three month average SOI was +0.9.

New Zealand’s warmest November on record.

New Zealand’s second-warmest spring on record

Summer temperatures are very likely to be above average across the country. Warm overnight temperatures and extended periods of high humidity are likely.

The NINO3.4 Index anomaly (in the central Pacific) during October was -0.59˚C. The latest weekly value was -0.80˚C, continuing the trend towards La Niña. The Southern Oscillation Index (SOI) was +0.7 during October and August-October, on the La Niña side of neutral. Overall, this represented an ocean-atmosphere system that was on the verge of La Niña conditions.