September 2019 was characterised by lower than normal mean sea level pressure over and to the southeast of New Zealand with above normal pressure to the west.
New Zealand Climate Update 244 - October 2019
7 October 2019
What happened in September how our climate outlook for the previous three months turned out, global and local sea temperatures, and our outlook for October-December.
The NINO3.4 Index (in the central Pacific) for the month of September (to the 29th) was equal to the 1981-2010 climatological value (i.e. zero anomaly). Above average warmth continued in the NINO4 region (west-central Pacific) with a monthly anomaly of +0.65˚C.
October – December 2019 temperatures have about equal chances of being near average (45% chance) or below average (40% chance) for the west and north of the South Island. All other regions of New Zealand will most likely experience near average temperatures (50% chance).
For the July to September period, air pressure was forecast to be higher than normal to the northwest of New Zealand and lower than normal to the south