Although mangrove forests play a role in climate control, including land surface temperature (LST), mangrove forests are reduced largely by changes in land use and land cover (LULC) by human activities. Expansion of the industrial landscape for establishing a special economic zone along Bangladesh coast has degraded nearby mangroves, which affects the LST of the area. Therefore, long-term dynamics of LST were analyzed at ten-year intervals using Landsat data from 1996 to 2025. LST, being associated with vegetation moisture and land cover differences, is increasingly applied in ecosystem assessment and environmental monitoring. The normalized difference vegetation index (NDVI), an indicator closely related to LST, showed an upward trend until 2014 but declined by 2025 due to mangrove loss driven by urban expansion. That year, the northern region recorded peak LST values exceeding 32.5°C. All LULC types showed an increase in LST. However, land recently converted from vegetated surfaces, such as forests, to built-up areas showed the highest LSTs. Analysis of 350 randomly sampled locations revealed a negative correlation between NDVI and LST, and a positive correlation between the normalized difference built-up index (NDBI) and LST. These results indicate that the combined influence of vegetation loss and built-up expansion primarily contributed to the rising LST in coastal ecosystems. Overall, these findings highlight the need for targeted land management strategies, especially around mangrove ecosystems, which play a critical role in regulating local climate.