An analysis of thermal stress of climate in Hong Kong

The universal scale of apparent temperature (AT) and do, a unit measuring the amount of clothing insulation required to maintain comfort, were used to examine the weather stress in Hong Kong. Hourly AT and do values were computed using hourly air temperature, wind speed, vapour pressure and cloud cover data from 1980 to 1994. Results of both AT and do reflected highly corresponding changes of thermal stress. It is found that the most stressful time in winter and summer occurred in the early morning and afternoon, and cool weather and tropical ensembles were required to surmount the extreme weather stress respectively. A greater percent of time with severe heat stress than those with extreme cold stress was discovered. These results also indicated that do is a more informative weather stress index than AT since it provides both the thermal stress and clothing requirements to sustain comfort.