Three lions die at zoo as Japan swelters in extreme heat

Three lions at Tama Zoological Park in Tokyo have succumbed to suspected heatstroke, with another three currently under treatment due to high humidity levels, the zoo reported. Japan experienced its hottest summer on record last year, with temperatures reaching up to 40C in certain regions, earning the new label "cruelly hot day".

Since mid-July, 10 out of the 16 lions in the park have exhibited symptoms such as loss of appetite and decreased activity. Tragically, three lionesses have died, with the latest death occurring today, following another death last Friday and a third demise on Sunday. The zoo's spokeswoman cited heatstroke as the probable cause, noting the lions' struggle with dehydration and multiple organ failure.

Despite lions being perceived as heat-resistant, the zoo has been enhancing its heat mitigation strategies, including water sprinkling, improved ventilation, and installation of spot air conditioners. The sudden onset of heat after the rainy season ended in late July exacerbated the situation. The zoo is intensifying its heat countermeasures.

Beyond the lion deaths, the extreme heat resulted in approximately 18,600 hospital visits for heatstroke between July 20-26, with 45 fatalities on arrival. Japan suffered around 1,300 heat-related deaths annually, with a goal to reduce this number by half by 2030. Climate scientists attribute the increased frequency and intensity of heatwaves in Japan and globally to human-induced climate change.

The country's highest recorded temperature was 41.8C in Isesaki, north of Tokyo, on August 5, 2025. Due to the escalating heat, authorities have adjusted the schedules of various cultural and sporting events, including the World Cosplay Summit in Nagoya, which last took place in its summer edition last weekend.