Aotearoa New Zealand has seen record high temperatures across many regions over the last week. This is not an isolated weather incident. In 2025 New Zealand's overall combined land and sea temperatures were the hottest ever measured.

The data comes from a new report released by Dr Jim Salinger with Climate Club New Zealand's Science Panel which considers temperature observations across Zealandia Te Riu-a-Māui.

The report highlights that 2025 recorded the highest average temperature in 151 years of continuous monitoring. All five of New Zealand's hottest years have occurred since 2018.

"These aren't just numbers on a page," says Dr Salinger. "This is the story of how our climate is changing, written in one of the longest and most reliable temperature datasets in the Southern Hemisphere. What we're seeing is an acceleration – the warming is speeding up, not slowing down."

In response to the findings, three of Aotearoa's leading independent climate scientists are issuing a nationwide challenge: as we head back to work and school this month, swap one car trip a week.

Transport accounts for 18.5% of Aotearoa's gross emissions. Replacing one out of every 5 car trips with active transport is estimated to save 1.3 million tonnes of CO per year, equal to the total annual greenhouse gas emissions of Fiji.

The nationwide challenge is issued by the Climate Club Science Panel, as part of their work to translate climate science into actionable guidance for New Zealanders.

"We hear from people all the time who feel overwhelmed and anxious, especially in the midst of heatwaves and news of the Australian bushfires," says Emily Mabin Sutton, Chief Executive at Climate Club NZ.

“But doing nothing guarantees the warming continues. Taking just one action feels doable, and is how we move from anxiety to agency. And these small actions, when millions of us do them, create real change."

New Zealanders can sign up to the Challenge at https://climateclub.nz/challenge. A simple process for encouraging workplaces and Councils to improve access to active and public transport is also available.

Resources

The full technical report, “New Zealand Temperature Tracker 2025”, is available at:
https://climateclub.nz/reports/new-zealand-temperature-tracker-2025/.

Sign up to the Challenge at https://climateclub.nz/challenge/your-challenge-swap-one-car-trip-a-week-as-we-head-back-to-work-and-school/?campaign-id=2

Additional information:

Dr Jim Salinger has tracked New Zealand temperatures since 1975. His early research provided some of the first evidence of warming in the Southern Hemisphere. He was named New Zealander of the Year in 2024 for services to climate science.

Temperature figures include observed land and sea temperatures from the 4.9 million square kilometres of Zealandia. When we only look at land temperatures, we're missing 94% of New Zealand's story. The warming of our surrounding oceans affects everything from our weather patterns to our marine ecosystems and fisheries. Our seas regulate our climate, support our fishing industry, and influence everything from rainfall patterns to storm intensity. Monitoring the full Zealandia territory gives us a more complete measure of climate change impacts on New Zealand.

Climate Club is a non-profit organisation working to transform anxiety into action through practical, achievable steps and advocacy for systems change. The organisation provides resources, workshops, and a community for those ready to take practical climate action.

The Climate Club NZ Science Panel brings together leading independent experts in climate science, international climate policy, and atmospheric science to advocate for climate action, and translates climate science into actionable guidance for New Zealanders. Launched in January 2026, the current members are:

• Dr Jim Salinger is a climate scientist with a focus on glacial ice and temperature change. He as a lead author for the Intergovernmental Panel on Climate Change, was made a Companion of the Royal Society of New Zealand in 2001 for services to climate science, holds the 2018 World Meteorological Organisation Award, the 2019 Jubilee Medal for lifetime achievements in climate and agricultural science, and in 2024 was named New Zealander of the Year.
• Dr Greg Bodeker is a New Zealand-based climate scientist who has held leadership roles with the World Climate Research Programme and the Global Climate Observing System. He is co-founder of Red Sky AI and Adjunct Professor at Victoria University's Climate Change Research Institute.
• Dr Carly Green is a carbon emissions and climate change policy specialist, and founder of Environmental Accounting Services, an organisation that supports governments and the primary sector with data and policy analysis that supports a science-based approach to climate mitigation and adaptation.

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