Increase in extreme day temperature in hills of Meghalaya: its possible ecological and bio-meteorological effect

Abstract

Climate change is also evident in northeastern India, indicates the analysis of long-term weather variables at Umiam, Meghalaya. This study focused on the change of temperature & humidity along with its possible effects. The mean annual temperature (Tavg) of Umiam has increased significantly over the last three decades. However, the annual maximum (Tmax) and minimum temperature (Tmin) exhibited a reverse trend, the former increased significantly from 24.3°C to 26.4°C from the late 1980s to 2015 while the later decreased significantly from 14.8°C to 13.8°C during the same period. Heat Index (HI) calculated from temperature and humidity data, showed a significant increase for most of the period of the year. There was a significant increase in the occurrence of extreme daily maximum temperature throughout the year. Different categories of HI have indicated varied response all over the year. The Normal category has shown a significant decreasing trend for the almost whole year, while caution, extreme caution and danger category days have depicted an increasing trend. But it can be seen that the months of May, June, and September showed a significant increase, which indicates towards upsurge of apparent temperature in these days. This may be linked with the monsoon to a large extent. Sometimes late arrival of monsoon increases the temperature in the May-June months and early withdrawal does the same for September. It calls for immediate precautionary measures for the people of the high-risk group. The changes have surely created a congenial environment for the animal disease vectors like mosquitoes and pose a greater indirect risk through the spread of the deadly diseases.