Glacial lakes (GLs) are integral components of the cryospheric environment. Due to the persistent melting of glaciers and steady rise in the annual mean temperatures, GLs are expanding across the Himalayan mountains. Since the 1980s, the eastern Himalaya have observed a steady increase (0.031°C/year) in annual mean temperature, causing rapid glacial melting, formation of new GLs and expansion of existing ones. Therefore, to assess the role of the increasing annual mean temperature on the expansion of GLs in the eastern Himalaya, we generated GL inventories for 1987, 2005 and 2018 for Dibang Valley district, Arunachal Pradesh, in the eastern Himalaya. We used Landsat multi-temporal satellite images along with the ASTER Digital Elevation Model V2 (DEM). Using the Segment Mean Shift (SMS) method, the GL inventories were generated. Our results show that there were 509 GLs in 2018, whereas only 484 in 2005 and 469 in 1987. GLs observed a growth rate of 8.52% in number and 11.13% in area between 1987 and 2018. Most of the GLs in the study area were of Moraine-dammed lakes (MDL) (~56%), whereas Ice-dammed lakes (IDL) showed the highest expansion rate between 1987 to 2018. GL hotspots show a concentration of GLs in the eastern and southern sections of Dibang Valley but new GLs are forming in the north-western and eastern sections of the study area. An increase in annual mean temperature enhanced the glacial melt water, leading to the growth of GLs connected with the glaciers.

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