Urban greening in arid environments faces competing pressures such as the need to enhance thermal comfort and ecological performance under severe water scarcity constraints. This study evaluates the effectiveness of vegetation interventions in Qatar by analyzing multi-spectral remote sensing data from 2016 to 2025 to assess whether municipal greening initiatives translate into measurable improvements in vegetation condition, surface moisture availability, and outdoor thermal comfort (OTC). Using Sentinel-2A imagery and gloUTCI-M, we computed four vegetation indices: Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Soil-Adjusted Vegetation Index (SAVI), Normalized Difference Moisture Index (NDMI) and the Universal Thermal Climate Index (UTCI) across eight municipalities with particular focus on Doha. Among vegetation indices, SAVI demonstrated robust performance under arid soil-dominated conditions, effectively accounting for soil reflectance where NDVI and EVI showed limitations. NDMI results revealed localized zones of moderate surface moisture, associated with irrigated and coastal urban areas, indicating management-dependent moisture retention rather than widespread hydrological improvement. Despite expanded greening and localized moisture availability, no statistically significant relationship between vegetation indices and UTCI was detected at municipal scale, a finding attributed to the dominance of non-vegetative thermal drivers and the detectability threshold of gloUTCI-M at 1 km resolution for patch-scale greening interventions. These results highlight the importance of distinguishing between greening extent and vegetation persistence, and of integrating vegetation strategies with urban form, shading, and microclimate-responsive design to improve thermal resilience in arid cities.