<p>Rapid urbanisation and land cover changes have intensified the prevalence of the Urban Heat Island (UHI) effect, wherein urban areas experience higher temperatures than their surrounding regions. Such a trend has been observed in the highly urbanized cities of Northeast India. However, there is a lack of studies that attempt to investigate the pattern of land cover change and UHI in such cities of Northeast India. Therefore, this study investigates the dynamics of Land Cover Change (LCC) and its impact on UHI patterns across the state capital cities of Northeast India between 1994 and 2024. Multi-temporal Landsat datasets (5, 8, and 9) were utilized for land cover classification using the Random Forest (RF) supervised machine learning classifier in Google Earth Engine (GEE) for the years 1994, 2004, 2014, and 2024. Land Surface Temperature (LST) was derived from thermal bands to assess UHI intensity over time. Ordinary Least Squares (OLS) and Geographically Weighted Regression (GWR) models were applied to examine the spatial correlation between LST and explanatory variables. The results revealed that during 1994–2024, Guwahati experienced significant growth in built-up areas, i.e., 93.17 sq. km (28.41%), while Itanagar exhibited low built-up growth, i.e., 17.11 sq. km (6.31%). LST analysis indicated a rising temperature trend across all cities except Shillong, which deviated from this pattern. A similar trend was observed in UHI intensity across most cities, except in Shillong, where a decline in UHI intensity was recorded. The comparative analysis of OLS and GWR models further revealed the distinct spatial heterogeneity of the relationship between LST and biophysical indices (NDBI &amp; NDVI). The study highlights the significant impact of urbanisation on surface temperature and the UHI intensity in the state capital cities of Northeast India. It also attempts to promote Sustainable Development Goals (SDGs) 11 and 13 by providing critical insights for climate-sensitive urban planning.</p>