In news:
Recently, India has been experiencing an unusual influx of heat waves. Temperatures have been soaring in an unrestrained manner over the past one month and a comparative study done by the National Aeronautics and Space Administration (NASA) in the past 30 days shows a yellowish blanket all over the country.
Heat Wave:
A Heat Wave is a period of abnormally high temperatures, more than the normal maximum temperature that occurs during the summer season in the North-Western parts of India.
Heat Waves typically occur between March and June, and in some rare cases even extend till July.

Temperature criteria : IMD
- Heat Wave need not be considered till maximum temperature of a station reaches atleast,40*C for Plains and atleast 30*C for Hilly regions.
- When the day temperature jumps by 4 to 5 degrees above the normal maximum temperature of a location, it is declared as a heat wave.
Previous such event:
In May 2015, India was struck by a severe heat wave. As of 3 June 2015, it has caused the deaths of at least 2,500 people in multiple regions.
Heat wave and climate change:
- Higher daily peak temperatures and longer, more intense heat waves are becoming increasingly frequent globally due to climate change.
- India too is feeling the impact of climate change in terms of increased instances of heat waves which are more intense in nature with each passing year, and have a devastating impact on human health thereby increasing the number of heat wave casualties.
Impacts of heat waves:
- The health impacts of Heat Waves typically involve dehydration, heat cramps, heat exhaustion and/or heat stroke.
- Further it also causes economic losses, loss of productive time and valuable human resources.
Churu in Rajasthan recorded 50 degrees Celsius on Tuesday, the district’s second-highest maximum temperature for May in the past 10 years. The Palam Observatory in Delhi on Wednesday recorded the highest maximum temperature at 47.2 degrees Celsius, slightly less than Tuesday’s 47.6 degrees Celsius.
Why the current event is unusual:
Heat waves usually occur by May 15.however, this year it be given by May 22 and is expected to last up to May 29.
This is attributed to two factors :
- Increase in the frequency of Western disturbances that cold the temperatures along the North Western part of India.
- The withdrawal of cyclone Amphan, which depleted its moisture in the coastal areas. This led to the influx of north-westerly dry winds.
Mitigation measures – Ahmedabad heat action plan:
- Building Public Awareness and Community Outreachto communicate the risks of heat waves and implement practices to prevent heat-related deaths and illnesses.
Disseminating public messages on how to protect people through media outlets, social media and orientation materials.
Special efforts to reach vulnerable populations through inter-personal communication from March to June annually.
- Initiating an Early Warning System and Inter-Agency Coordination to alert residents of predicted extreme temperatures.
The AMC has created formal communication channels to alert government agencies, health officials and hospitals, emergency responders, local community groups, and media outlets of extreme temperatures forecasted by the IMD.
- Capacity Building among Health Care Professionals to recognize and respond to heat-related illnesses, particularly during extreme heat events.
- With greater emphasis on prevention and management of heat-related cases and reduce mortality and morbidity.
- Reducing Heat Exposure and Promoting Adaptive Measures by launching new efforts including mapping of high-risk areas of the city, broadening outreach and communication on prevention methods, and increasing access to potable drinking water and cooling spaces on extreme heat days.
- Collaboration with non-governmental organizations to expand outreach and communication with the city’s most vulnerable communities.
Such effective heat wave action plans are to be replicated in all states that are vulnerable to extreme heat events.
In the coming years India will be witnessing many such events. It should be ready to mitigate, adapt and become resilient to them. The above measures are to be implemented effectively.
Source:” NDMA“.
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