Humid‑heat flagged for India
A new study highlighted that humid heat — measured by rising wet‑bulb temperatures — is emerging as India’s most dangerous climate threat and identified Kerala as particularly exposed. (downtoearth.org.in)
Humid heat in India is not just about hotter air. A 2026 study found the country’s most dangerous heat risk is rising wet-bulb temperature — heat plus humidity — with Kerala especially exposed. (downtoearth.org.in) Wet-bulb temperature measures how hard it is for sweat to cool the body. When humidity is high, sweat evaporates poorly, core temperature rises faster, and heatstroke can follow within hours even at temperatures that look less extreme on a standard thermometer. (downtoearth.org.in) The paper, published in *Climate Dynamics* in 2026, was led by Akshay Deoras of the University of Reading and used more than 80 years of weather data. It linked India’s humid-heat risk to the southwest monsoon, not just to isolated hot days. (link.springer.com) The study found that monsoon “break” periods favor moist heatwaves in eastern and peninsular India, while active rainfall phases favor them in northern and northwestern India. In Kerala, the coastal districts face higher risk than inland areas during monsoon breaks. (link.springer.com) (newspointapp.com) Kerala’s exposure is tied to geography as much as to warming. The state’s long coastline, dense vegetation and monsoon climate already keep humidity high, and warmer nights leave less time for the body to recover from daytime heat. (downtoearth.org.in) The mechanics sit inside a larger monsoon pulse called the Boreal Summer Intraseasonal Oscillation, a shifting pattern that helps decide where humid heat builds. The study says those monsoon patterns can be forecast weeks ahead, giving authorities a longer warning window than a same-day heat alert. (downtoearth.org.in) (link.springer.com) The paper also found that specific humidity mattered more than dry-bulb temperature in controlling wet-bulb variability across India. That means places can become more dangerous without posting the country’s headline-highest air temperatures. (link.springer.com) India’s heat alerts have long leaned on temperature thresholds, and researchers say that misses part of the danger in coastal and monsoon-season heat. Deoras said moist heat remains less recognized than dry heat in India, even though it can turn outdoor work and public gatherings into medical emergencies. (downtoearth.org.in) (reading.ac.uk) That leaves Kerala at the front edge of a wider shift in how India has to read heat danger. The thermometer still matters, but the study says the air’s moisture load may now decide where the greatest risk lands. (downtoearth.org.in) (link.springer.com)
