Most of New Zealand is drier than average. Most of NZ is warmer than average. Now the sea surface temperatures are not only above average, but they are warmer than average more so than anywhere else on the globe.

Current sea surface temperatures between New Zealand’s South Island and Australia’s south eastern corner (the south half of the Tasman Sea) are well above average, by over 6 degrees. Often a couple degrees above average can make news headlines, six degrees is quite extraordinary. 

WeatherWatch.co.nz head forecaster Philip Duncan says the lack of movement in the weather around New Zealand over the past several weeks has contributed. “The Tasman Sea is basically like a bath with the hot tap on and the cold tap isn’t turned on properly. With no big Tasman Sea lows or strong southerly wind flows we’re instead seeing warm ocean currents, which hug Australia’s eastern coastline, drift across the Tasman Sea. There’s no churning motion to mix warm and cool”.

The West Coast of the South Island now has similar temperatures to those swimming in northern beaches around Bay of Plenty, Auckland and Coromandel Peninsula. Sea surface temperatures are around 19 degrees in the west and north. Generally speaking sea surface temperatures around New Zealand don’t peak until March.

ABOVE – Sea surface temperatures in yellow/yellowy-white are over 6 degrees above normal for now.
BELOW – The Tasman Sea area is much warmer than average, more than anywhere else on the planet.  Images via GFS/Earth.nullschool.net

WHAT ABOUT RAINFALL?  WHEN WILL NEW ZEALAND GET RAIN?
Warmer oceans leads to bigger storms and more downpours, so the current set up basically highlights something WeatherWatch.co.nz first mentioned about this coming summer back in October – that it may have a mix of droughts and some isolated flood events.

The 10 day trend for New Zealand shows some improvement to previous updates in November, with less extreme red and more blue coming back in. (See map below).

However, the general trend is for much of New Zealand to remain hotter and drier than average.

Daily downpours may return to inland areas as well this week, but won’t be as widespread as last week. 

10 DAY FORECAST RAINFALL MAP COMPARED TO AVERAGE:

– Red = much drier than average. Pink = Mostly dry, some showers. White = Average rainfall. Blue: Wet, perhaps wetter than average (if dark blue).  GFS (US Govt).

– WeatherWatch.co.nz