Millions of Australians living in major cities could face increasingly large and intense hailstorms in the future, according to a new study by the University of New South Wales’ Sydney Institute for Climate Risk and Response.
The research identifies Sydney, Canberra, Melbourne, and Perth as particularly vulnerable to these more damaging hail events as global temperatures rise.
Lead author Dr. Tim Raupach explained that climate change is expected to increase hail size in some capital cities, based on simulations comparing historical and future weather patterns.
However, cities like Adelaide showed little change in hailstorm intensity in the models, highlighting the complexity of hail prediction.
Hailstorms have accounted for more than 20% of insured losses in Australia between 1967 and 2023, with damage severity largely linked to hailstone size. The largest recorded hailstone in Australia measured approximately 16 cm in diameter near Mackay, Queensland—more than twice the size of a cricket ball.
Dr. Raupach noted that future storms may produce hailstones more frequently and of larger size. For instance, hailstones measuring 10 cm, which previously occurred once every 20 years around Melbourne, could happen as often as once every three years in a warmer climate.
Although hailstones form from ice, warm atmospheric conditions are essential to their development. Strong updrafts in thunderstorms lift moisture high into the atmosphere, where it freezes and accumulates layers of ice to form hailstones.
The east coast of Australia, from just north of Brisbane to south of Sydney, remains the most hail-prone region.
One growing concern is the vulnerability of solar panels to hail damage, though Raupach emphasized that this risk should not discourage investment in renewable energy.
He also stressed the need to strengthen urban infrastructure to better withstand hailstorms, particularly if hailstone sizes continue to increase due to climate change.
In the meantime, Australians are encouraged to prepare for hail by seeking shelter, protecting vehicles, securing good insurance, and using durable roofing materials. Some farmers have adopted hail nets to protect crops.
Dr. Joanna Aldridge from QBE Insurance, co-author of the study, pointed out that current Australian building standards do not require hail resistance, leaving many properties exposed.
Raupach urged both immediate and long-term actions, including reducing greenhouse gas emissions and further research into hailstorm patterns and their impact on urban areas.
He suggested that in the future, city designs might incorporate features to reduce storm risks, though such developments remain in the early stages.
