The relocation of the Indonesian capital from Jakarta to Ibu Kota Nusantara (IKN) East Kalimantan IKN will affect several sectors. The change in land use from vegetated to developed land will lead to local climate changes, including the emergence of the urban heat island (UHI) phenomenon, which is reflected in a higher land surface temperature (LST) than the surrounding area. In this study, an analysis of UHI propagation was conducted on a seasonal (DJF, MAM, JJA, and SON), with 5 yearly periods from 2001 to 2020, study area in IKN and its buffer cities (Balikpapan, Samarinda, and Bontang). Terra-MODIS satellite data are processed using Google Earth Engine (GEE) platform and output is done using GrADS. UHI (high LST) is found in urban areas/buffer cities both spatially and temporally in every season, while UHI has not yet occurred in IKN (low LST) and suburban, rural, hilly areas, vegetated areas, and water bodies (lakes, rivers). The cross-sectional latitudinal and longitudinal analysis showed that the LST DJF2015-2020 from highest to lowest temperature are in Balikpapan City (36.84 OC), Samarinda City (36.13 OC), Bontang City (32.3 OC); and IKN zero point (28.82 OC). The UHI propagation was observed in 2001-2005, 2006-2010, 2011-2015, and most during 2016-2020. Seasonally, the UHI was most pronounced in the SON season, while on lowest UHI was observed in the MAM season.