What is the Heat Index?

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What is the Heat Index? Blog Image


Recently, the Union Minister of Earth Sciences informed that the India Meteorological Department (IMD) has launched the Heat Index on an experimental basis.

About Heat Index: 


  • It provides information about the impact of humidity on the high temperatures and thus provides a feel like temperature for human beings which can be used as an indication for human discomfort.
  • It provides guidance towards additional care to be taken by people to reduce discomfort.
  • Colour codes used for Experimental Heat Index are as follows:
    • Green:  Experimental heat Index less than 35 deg C
    • Yellow: Experimental heat Index in the range 36-45 deg C
    • Orange: Experimental heat Index in the range 46-55 deg C
    • Red: Experimental heat Index greater than 55 deg C
  • The Heat Index is implemented on experimental basis only across the entire country including the State of Andhra Pradesh.
  • At present, heat index is derived using the heat index equation similar to what is used by National Weather Service, National Oceanic and Atmospheric Administration (NOAA), USA.


Key facts about IMD

  • It is the main agency responsible for meteorological observations, weather forecasting and seismology in India.
  • It operates hundreds of observation stations across India and Antarctica.
  • Regional offices are in Chennai, Mumbai, Kolkata, Nagpur, Guwahati and New Delhi.
  • It has the responsibility for forecasting, naming and distributing warnings for tropical cyclones in the Northern Indian Ocean region, including the Malacca Straits, the Bay of Bengal, the Arabian Sea and the Persian Gulf.
  • Nodal Ministry: Ministry of Earth Sciences.


Q1) What is Humidity?

Humidity refers to the amount of water vapor present in the air. It is a crucial factor in weather and climate, as it can greatly influence how humans perceive temperature and comfort. Humidity levels are measured using devices called hygrometers and are usually expressed as a percentage.

Source: Shri Kiren Rijiju says IMD has launched Heat Index