About the climate projections
Projections show how the climate change could change in Aotearoa New Zealand over the rest of this century.
Climate projections are modelled representations of the potential future climate over the next several decades. Projections are not predictions, but rather a representation of how different future climates might unfold. We can use them to help us to assess the potential future impacts of climate change, inform decision-making about how to adapt to risks and opportunities, and increase our resilience to extreme weather events.
The projections are based on data from global climate models assessed in the Intergovernmental Panel for Climate Change (IPCC) Sixth Assessment Report [IPCC], published in August 2021. This IPCC report was based on the latest suite of around 100 global climate model outputs.
See Aotearoa New Zealand climate change projections guidance for more details.
NIWA
The National Institute of Water and Atmospheric Research (NIWA) selected six global models from this set and completed a process known as downscaling (translating the data into finer resolution simulations). This process has provided New Zealand specific projections at a 5 km grid scale.
This work has been funded by the Ministry for Business, Innovation and Employment and delivered by NIWA, the Ministry for the Environment, and Climate Data Initiative.
See updated national climate projections for Aotearoa New Zealand [NIWA]
You can use this data to assess projected changes in several climate variables such as:
- rainfall
- temperature
- wind speed
- humidity.
The dataset is aggregated into historical and future 20-year periods. The data is the average (mean) of the values produced by each of the six climate models used by NIWA for the downscaling process.
The climate projections can tell us about the change in climate (eg, how much rain there might be) but not hazards or exposure to risks (eg, how much flooding the rain will cause, or which homes might be affected by flooding).
We expect the data to be useful to councils or businesses as they make plans for adapting to climate change.
The data is publicly available for anyone to access and use.
The original data has been transformed into a standard NZ geospatial projection (EPSG:2193). This process can result in slightly different values from the original data at particular locations. Grid squares with missing data around the coasts were filled based on a weighted averaging of neighbouring grid squares. Applying these two processes may produce slightly different maximum, minimum, and mean values for spatially aggregated areas, such as territorial authorities, compared to the original data.
Only tiles which have their centre in the mapped area were included for the aggregated areas.
For further information please contact the Climate Data Initiative team.