Heatwave in States, including Jharkhand | 05 Apr 2024

Why in News?

Recently, the India Meteorological Department forecast heatwave conditions in parts of Karnataka, Odisha, West Bengal, Jharkhand, Andhra Pradesh and Yanam over the next two-three days.

Key Points

  • The weather department has forecast a harsh and arid summer over a majority of regions of the country during April-June 2024.
    • There is a high probability of heatwave episodes lasting in a range of 10 to 20 days during the period.
  • During April, the performance of the pre-monsoon rainfall shall be below average, mainly over coastal India, eastern and south peninsular India.
    • The rainfall forecast indicates that the dry weather since February 2024 would continue over these regions.
    • Aridity and shortage of water will aggravate during the summer season of 2024.

Heatwaves

  • Heatwaves are prolonged periods of excessively hot weather that can cause adverse impacts on human health, the environment, and the economy.
  • India, being a tropical country, is particularly vulnerable to heatwaves, which have become more frequent and intense in recent years.
  • IMD Criteria for Declaring Heat Wave in India:
    • Heat waves need not be considered till the maximum temperature of a station reaches at least 40°C for Plains and at least 30°C for Hilly regions.
    • If the normal maximum temperature of a station is less than or equal to 40°C, then an increase of 5°C to 6°C from the normal temperature is considered to be heat wave condition.
    • Further, an increase of 7°C or more from the normal temperature is considered a severe heat wave condition.
    • If the normal maximum temperature of a station is more than 40°C, then an increase of 4°C to 5°C from the normal temperature is considered to be heat wave condition. Further, an increase of 6°C or more is considered a severe heat wave condition.
    • Additionally, if the actual maximum temperature remains 45°C or more irrespective of normal maximum temperature, a heat wave is declared.