Climate Change Expected to Reduce Optimal Temperatures at 86% of Global Marathons by 2045

A new analysis by Climate Central highlights that climate change is significantly reducing the chances of optimal temperatures for elite marathon runners, jeopardizing record-breaking performances globally. The study reviewed 221 marathons, including all seven Abbott World Marathon Majors, and found that 86% of these races are expected to see a decline in ideal running conditions by 2045, with Tokyo currently offering the highest odds for men but facing the steepest decline. Elite men perform best around 4°C, while elite women perform better at slightly warmer temperatures near 10°C, yet global warming is making these ideal conditions increasingly rare. Athletes like Mhairi Maclennan express concern that rising temperatures not only make races harder but threaten the possibility of achieving peak performances. Former champions such as Catherine Ndereba and Ibrahim Hussein emphasize that climate change is now an intrinsic challenge to marathon running, urging environmental protection to preserve the sport's future. The 2025 Tokyo and Berlin Marathons already demonstrated heat levels exceeding optimal thresholds, underscoring the urgent need for adaptations like rescheduling endurance events to safer periods.