Outlook: May-July 2018

May – July 2018 temperatures are forecast to be above average (50% chance) in the north of the North Island and average (40% chance) or above average (40% chance) for all remaining regions of New Zealand.  Despite the prospect for average or warmer than average temperatures, frosts and cold snaps will become more common, with some cold snaps possibly quite sharp.

May – July 2018 rainfall totals are forecast to be above normal (45% chance) in the north of the North Island, near normal (40% chance) or above normal (40% chance) for the rest of the North Island as well as the east and north of the South Island.  Normal (40% chance) or below normal (45% chance) rainfall is expected for the west of the South Island.  The combination of lower than normal sea level pressure over the New Zealand region and warmer than average Tasman Sea temperatures over the coming months will result in an elevated chance for significant rainfall events.

May – July 2018 soil moisture levels and river flows are expected to be near normal or above normal (40 – 45% chance) for all North Island regions and for the north of the South Island.  For the east of the South Island, river flows are also expected to be near normal or above normal (40 – 45% chance), but with soil moisture levels forecast to be above normal (50% chance). For the west of the South Island, soil moisture levels and river flows are forecast to be normal (40% chance) or below normal (40% chance). 

Graphical representation of the regional probabilities, Seasonal Climate Outlook, May-July.