Methane emissions from landfills pose a growing environmental challenge in Indonesia, where the increasing generation of waste is met by limited monitoring of these emissions. As one of the most significant anthropogenic sources of methane, landfills contribute significantly to national greenhouse gas (GHG) emissions. This study examines the spatial distribution, temporal variation, and comparative dispersion patterns of methane from two landfills, Griyomulyo and Sekoto, utilizing AERMOD modeling. Spatial delineation (2006–2024) and emission estimates from four models (IPCC, LandGEM, Afvalzorg, and Thailand) were input into 24-hour and 1-month simulations for 2021, 2022, and 2025. Dispersion outputs were overlaid with village boundaries to identify communities within high-exposure zones. Griyomulyo exhibited broader dispersion due to higher waste generation and flat topography, while Sekoto showed more localized and less intense patterns. In the Thailand 2025 scenario (24-hour, 500 µg/m³ threshold), Griyomulyo’s plume reached 20,268.9 meters, covering 24,194 hectares and affecting 11 villages—over twice the extent of Sekoto. Dispersion behavior varied based on model choice, simulation duration, and site-specific conditions. These findings highlight the spatial variability of landfill methane emissions and emphasize the need for location-specific assessments to support sustainable mitigation strategies in Indonesia’s solid waste sector.