Investigation of the degree of human thermal discomfort using empirical analysis of weather parameters in Guwahati, Assam

Abstract

The present investigation deals with the degree of Thermal Discomfort (TD) by analyzing key weather parameters in Guwahati, Assam which is known for its humid subtropical climate. These weather parameters are compared during 1991 to 2020 and 2022-2024 through various climatic diagrams e.g., Taylor’s Climograph,  Hythergraph etc. in order to understand the impacts of these parameters on TD, crucial for optimizing agricultural practices as well as improving human well-being. Taylor’s Climograph, employing a 12-sided polygon to graphically represent monthly Wet Bulb Temperature (WBT) and Relative Humidity (RH) used in this study to provide insights into climatic patterns and associated discomfort levels. Similarly, Hythergraph is also incorporated to understand the rainfall-temperature relationship during these periods of time. Additionally, Heat Index (HI), a metric combining air temperature and RH to estimate perceived temperature ("feels-like" conditions), offered a comprehensive assessment of thermal stress for this study. The highest degree of discomfortability (hot and humid; termed as “muggy” after Taylor) was found in the months of June, July, August and September with more extreme during 2022-2024 compared to 1991-2020. HI analysis showed that maximum temperature (Tmax) exceeded 40°C during May to October, with the highest perceived temperature peaked at 55.5°C in September during 2022-24 which is classified as “Extreme Danger” where heat stroke is highly likely. Considering the hot and humid conditions during the pre-monsoon (May), monsoon (June-September) and post-monsoon (October) as reflected in the present assessment, it is crucial to monitor agricultural fields to maintain optimal soil moisture and nutrient levels. For human health, this study emphasized the importance of staying hydrated and minimizing exposure to direct sunlight. By integrating Climograph, Hythergraph and HI data, this research identified critical periods of TD and provided adaptive strategies for agriculture and public health, aiding informed decision-making in regions like Guwahati amidst climate change.