Bioclimatic classification of 19 stations in India in terms of cumulative heat stress

Abstract

The paper makes an attempt to outline a rational approach towards bioclimatic classification of the climates of Indian stations, in relation to human comfort and efficiency, keeping in view the nature and quantum of relevant available meteorological data. A simple and practical index of monthly cumulative heat stress has been defined and termed as Monthly Excess Maximum Effective Temperature days (MEMET), which has been found to correlate very well with Excess Discomfort Index Hour-Days based on mean hourly values of dry and wet bulb temperatures during daylight hours. This index has been utilised for grading 19 Indian stations in descending order of cumulative discomfort for (i) the hottest month of the year, (ii) average of the three hottest months of the year, and (iii) average-of eight months from March to October. Tentative assessment of the air conditioning needs has also been made on a monthly basis in terms of MEMET values. Findings are applicable to average acclimatised Indian adult males in normal summer clothing, resting or engaged in sedentary duties indoors with an average wind speed of 150 ft/min (2.7km/hr).