As per the Indian Meteorological Department (IMD), Heat wave is considered:

OPTIONS

(A) If maximum temperature of a station reaches at least 40C or more for Plains

(B) If maximum temperature of a station reaches at least 37C or more for coastal stations

(C) If maximum temperature of a station reaches at least 30C or more for Hilly regions

(D) All of the above


NOTES
Answer D

Explanation: What is a heatwave?

The IMD says heatwave is considered when the maximum temperature of a station touches at least 40 degrees Celsius or more for plains, 37 degrees Celsius or more for coastal regions and at least 30 degrees Celsius or more for hilly regions.

What are the criteria?

Heatwave is declared when the departure from normal temperature is by 4.5 to 6.4 degrees Celsius and a severe heatwave is when the departure from normal is more than 6.4 degrees Celsius.

For plains, based on actuals maximum temperature, IMD considers heatwave when actual maximum temperature is more than 45 degrees Celsius and severe heatwave when it is more than 47 degrees Celsius.