As several parts of the country experience heatwaves, and with summer temperatures steadily on the rise, India is set to get its own heat index. Starting this month, the India Meteorological Department (IMD) for the first time will introduce a heat index for the country. The index will be available on the IMD website, and will be updated every three hours across all weather stations. A heat index – a measure of how hot it really feels – is calculated based on actual temperatures and relative humidity levels. The index will give citizens accurate and updated information on the heat conditions specific to their areas.

• For instance, a heat index between 40 and 54 with humidity levels less than 70% and more than 70% is termed is ‘uncomfortable’ and ‘uncomfortable sultry’.
• With yellow and orange as warning colour codes respectively, the health hazards read “heat cramps and heat exhaustion likely”.
• Similarly, a green colour code with a heat index less than 40 is ‘comfortable’ with no health hazards, while a heat index of more than 54 means ‘highly uncomfortable hot’ (orange) and ‘highly uncomfortable sultry’ (red) indicating a likelihood of heat stroke or sun stroke.