A new study by the U.S.-based nonprofit Climate Central shows that rising global temperatures could make it much harder for runners to achieve record-breaking times in major marathons.
Analysing 221 marathons scheduled for 2025, the report finds that around 86% of them are expected to see a drop in the likelihood of ideal race-day temperatures by 2045.
For elite men, the “sweet spot” for a marathon finish is around 4 °C (≈39 °F), while for elite women it’s about 10 °C (≈50 °F).
Several of the major marathons are already being affected: for instance, the Berlin Marathon in September recorded a spring-too warm temperature of about 24 °C (≈75 °F).
The report highlights that even top-tier races such as the Tokyo Marathon, currently offering the highest chance of ideal weather for elite men (69%), will face steep declines in favourable conditions by mid-century.
Athletes and former champions are sounding the alarm. Catherine Ndereba, a former world-record holder, noted: “Climate change has altered the marathon … dehydration is a real risk, and simple miscalculations can end a race before it begins.”
The takeaway: unless we curb warming trends and rethink how and when races are held (for example, earlier starts or scheduling shifts), the era of ever-faster marathon finishing times may be drawing to a close.
Discussion about this post