Scientists found that hot weather affects our moods more than we realize. They analysed over one billion posts from 150 countries. When temperatures passed 35°C, negativity increased, especially in less wealthy regions. Heat made people less positive, less patient, and more irritable.
Researchers from MIT and global partners rated 1.2 billion posts by sentiment and tied them to local weather. The hotter the day, the more negative words appeared. In poorer countries, negative reactions were three times stronger than in richer ones.
Heat and Human Behaviour
Evidence linking hot weather and aggression is long-standing. Drivers honk more in traffic during heatwaves. Journalists use harsher language on hot days. Studies also connect heat with crime, violence, and even suicide. One study showed more murders in Greece on hot days. Historical analysis revealed uprisings often erupted in summer months worldwide.
Scientists think heat may alter brain chemistry or increase hormones linked to aggression. They caution that while hot weather and bad moods often align, other factors may play a role.
What the Future Holds
Climate models suggest rising heat could reduce collective positivity by 2.3% this century. This emotional burden could hit hardest in vulnerable communities already exposed to extreme conditions. Researchers warn that climate adaptation must consider mental and emotional health, not just physical safety.
As temperatures rise, societies must prepare not only for heat’s physical dangers but also its unseen impact on human emotions.
