One definition of a heat wave is that it is an unbroken period of least 5 days when daily maximum temperature at a place is at least 5°c higher than t, where t is the normal maximum temperature for the hottest month of the year. what could be problematic about this definition?
(i) t varies from location to location.
(ii) near the equator, temperature almost never fluctuate beyond 5°c above t.
(iii) prolonged periods of extreme heat can be temporarily interrupted by less hot weather of one or two days at a specific place due to local weather.