Outlook: June-August 2018

June – August 2018 temperatures are forecast to be near average (40% chance) or above average (35% chance) in the north and west of the North Island, near average (40% chance) or below average (35% chance) in the east of the South Island, near average (40% chance) for all other regions of the country. Periodic northeasterly air flows during the first half of winter in particular may bring mild periods to northern areas. Westerly-quarter (NW to SW) winds during the second half of the winter season may lead to cooler conditions in southern and western areas.

June – August 2018 rainfall totals are forecast to be near normal (35 to 40% chance) or above normal (35 to 40% chance) in the north and east of the North Island and east of the South Island. Normal (35 to 40% chance) or below normal (35 to 40% chance) rainfall is forecast in the west of both islands with near normal rainfall expected in the north of the South Island. Lower than normal air pressure to the west and north of New Zealand during June may bring a few heavier rain events to the north and east of the North Island and perhaps east of the South Island.

June – August 2018 soil moisture levels and river flows are expected to be above normal (45% chance) in the north of the North Island. For the east of the North Island and north and west of the South Island, soil moisture levels and river flows are forecast to be near normal (40-50% chance). For the west of the North Island, soil moisture levels and river flows are expected to be above normal or near normal (40-45% chance). For the east of the South Island, soil moisture levels and river flows are expected to be near normal or above normal (35-40% chance).

Graphical representation of the regional probabilities, Seasonal Climate Outlook, June-August.