The Auckland region has a sub-tropical climate with warm humid summers and mild winters.
Typical summer daytime maximum temperatures range from 22ºC to 26ºC and rarely exceed 30ºC. Winter daytime maximum temperatures range from 12ºC to 17ºC. Annual sunshine hours average about 2000.
Winter usually has more rain and is the most unsettled time of the year. In summer, storms of tropical origin may bring high winds and heavy rainfall from the east or northeast. The El Niño Southern Oscillation also has a large impact. Annual maximum rainfall during La Niña events is generally larger and more variable than the extremes during El Niño events.
Rates of climate change
Rates of climate change depend on future global emissions of greenhouse gases, which depend on global social, economic and environmental policies and development. You need to consider a range of possible features when assessing climate impacts and developing adaptation strategies.
Climate change will influence many of Auckland’s natural hazards. Reductions or increases in magnitude and changes to the location and frequency of hazards may be experienced.
The International Panel on Climate Change has provided climate projections for New Zealand for 2040 and 2090.
Their Auckland projections include:
- Increase in the mean air temperature.
- Increase in sea level due to thermal expansion within oceans and loss of ice sheets and glaciers on land.
- Fewer periods of cold temperatures and an increase in the number and intensity of periods of high temperatures. We’ll have more days above 25ºC.
- Decrease in annual mean rainfall.
- Increased frequency and intensity of extreme rainfall events due to a warmer atmosphere.
- Increased intensity of El Niño and a possible increase in El Niño frequency with an associated increase in the annual mean westerly wind flow.
- Possibly more intense extra-tropical cyclones bringing torrential rain, strong winds and storm surges.
Impacts of climate change
We don’t know exactly how climate change will affect Auckland.
Various impacts would heighten social, economic and environmental challenges.
- Health problems from extreme temperatures.
- Damage to properties and critical infrastructure from more intense inland flooding and coastal inundation.
- Coastal erosion from larger waves hitting the coastline.
- Disruption to agriculture and horticulture from water supply issues and more severe drought.
- Fire from increased drought frequency, windier conditions and fire suppression difficulties.
Visit The Ministry for the Environment and the National Institute for Water and Atmospheric Research (NIWA) websites.