This research was conducted to quantify the influence of changes in biophysical parameters on the regional thermal dynamics in the Bakhtegan-Maharlu watershed during March, across the period from 1991 to 2020. To achieve this objective, Landsat 5th and 8th generation satellite data were processed utilizing the Google Earth Engine platform for the extraction of the specified indices. Subsequently, Pearson correlation analysis and multivariate regression modeling were employed to elucidate the relationship between the biophysical variables and the thermal characteristics. Furthermore, Hot Spot Analysis was implemented to identify and spatially locate high-intensity thermal clusters. Findings revealed a significant and severe decline in the NDWI index across the Bakhtegan and Maharlu lakes, concomitant with a decrease in NDVI in the surrounding areas. These land surface transformations resulted in the expansion of warmer temperature classes (from 30−40^∘C to a new class of 40−50^∘C) in the southern and central parts of the basin, underscoring an increasing trend across all investigated temperature parameters. The spatial analysis indicated that high-intensity thermal clusters were predominantly concentrated in the southern and southeastern regions of the watershed; this spatial convergence was directly correlated with areas exhibiting the highest LST values, reduced water resources, and severe vegetation destruction.