HEAT WAVES

Why in News?                                                                                                        

Prime Minister Shri Narendra Modi chaired a meeting to review preparedness for the ensuing heat wave season.

What is Heat Waves?

• 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.
• The extreme temperatures and resultant atmospheric conditions adversely affect people living in these regions as they cause physiological stress, sometimes resulting in death.
• The Indian Meteorological Department (IMD) has given the following criteria for Heat Waves.
• Heat Wave need not be considered till maximum temperature of a station reaches at least 40°C for Plains and atleast 30°C for Hilly regions.
• When normal maximum temperature of a station is less than or equal to 40°C Heat Wave Departure from normal is 5°C to 6°C Severe Heat Wave Departure from normal is 7°C or more.
• When normal maximum temperature of a station is more than 40°C Heat Wave Departure from normal is 4°C to 5°C Severe Heat Wave Departure from normal is 6°C or more.
• When actual maximum temperature remains 45°C or more irrespective of normal maximum temperature, heat waves should be declared.
• Higher daily peak temperatures and longer, more intense heat waves are becomingly 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.