Weather

The weakening of the Southern Annular Mode and the Indian Ocean Dipole and the forecast for ENSO to remain neutral over the next three months indicate the absence of strong, persistent climate drivers for New Zealand.

Wet end to the year for much of New Zealand.

Temperatures for the summer season are expected to be above average for New Zealand, apart from the west of the South Island where there are about equal chances for near average or above average temperatures.

Average temperatures overall with variable rainfall patterns.

For October to December, air pressure is forecast to be lower than normal in the New Zealand region, especially south of the country. This is expected to be associated with a westerly quarter air flow anomaly, particularly during November and December. Occasional easterly quarter winds are possible during October.

Variable temperature and rainfall patterns with frequent southwesterly winds.

7th-warmest winter on record and near normal rainfall

The central Pacific El Niño event that arrived in March 2019 has ended, giving way to ENSO neutral conditions, owing to cooling sea surface temperatures (SSTs) in the tropical Pacific and a neutral Southern Oscillation Index (SOI) during August.

New Zealand’s 2nd-warmest July on record.

Despite a sharp cold snap in early August, seasonal temperatures are forecast to be near average or above average for all regions of New Zealand, owing to warmer than average coastal and regional sea surface temperatures.

An unusually dry start to winter.

A weak, central Pacific El Niño continued during June as sea surface temperatures (SSTs) remained more than 0.7˚C above average (i.e. the El Niño threshold) for the fourth consecutive month.

Although El Niño is forecast to continue during the upcoming three-month period, it may weaken later in 2019. Winter temperatures are forecast to be above average in the east of the South Island and to be above average or near average in all remaining regions.