This is a sub-tropical climate zone, with warm humid summers and mild winters.

If you list all the historic rainfall totals for a particular month and for a specific location, rank these from lowest to highest, then divide the list into ten equal parts, you have identified the ten rainfall deciles for that month and for that location.

A summary of up-coming tropical cyclone seasons, issued 6-monthly.

A handful of species we work on

Water take (also known as water abstraction) has a range of valuable public and private uses.

When fresh water meets salty water - a classroom exercise that explores the physics of estuaries.

Northland, with its northern location, low elevation and close proximity to the sea is characterised by a mild, humid, and rather windy climate.

Dog Island levels

Where and when do white sharks occur in New Zealand waters, and how can fisheries bycatch be reduced?

Various industries and land use activities have the potential to impact on water quality and mahinga kai unless properly managed.

New Zealand’s forests and other land areas may be absorbing up to 60% more carbon dioxide than has been calculated, with much of this uptake likely occurring in native forests, NIWA scientists have discovered.