Urban heat stress in semi-arid Algerian cities, such as Biskra, remains insufficiently studied. Investigating its spatial and temporal dynamics through integrated RS and GIS approaches is crucial for advancing sustainable urban planning and climate adaptation strategies. This study aims to analyze the spatial and temporal variations in land surface temperature (LST) between 2011 and 2022 in Biskra, Algeria, using Remote Sensing (RS) and Geographic Information Systems (GIS) techniques. It further seeks to identify the zones most affected by elevated LST and to examine their relationship with vegetation, built-up, and water indices (NDVI, NDBI, NDWI). The results reveal significant seasonal and decadal variations in land surface temperature (LST). During the summer months, LST exceeded 45 degrees C in several urban zones, reflecting strong heat accumulation and limited vegetation cover. In contrast, cooler months recorded temperatures below 20 degrees C, associated with higher vegetation and water presence, indicating improved ecological quality. Overall, the findings highlight how urban expansion and seasonal variability have intensified heat stress and degraded environmental conditions in Biskra semi-arid context. The analysis reveals marked seasonal and decadal variations in urban heat across Biskra, with higher LST, intensified Surface Urban Heat Island (SUHI), and lower Urban Thermal Field Variance Index (UTFVI) values indicating pronounced heat stress and reduced ecological quality during summer, contrasted by cooler and more balanced conditions in other seasons. These results emphasize the impact of urban expansion and seasonal variability on thermal stress and the vulnerability of Biskra urban environment, highlighting the need for vegetation-oriented and sustainable urban planning. Future research should employ higher-resolution data and predictive modeling to better understand urban thermal dynamics under climate change.