Colombia's national annual average PM2.5 concentration decreased modestly from 13.8 μg/ m3 in 2024 to 11.1 μg/m3 in 2025. Annual average concentrations declined slightly across all highlighted cities, including Bogota, Medellin, Bello, and Envigado. Bogota continued its average concentration at or below 10 μg/m3. Temperature inversions contributed to higher monthly PM2.5 concentrations across analyzed Colombian cities in February and March compared to other months of the year. Despite these seasonal increases, no city reported a monthly average concentration above 25 μg/m3, in contrast to last year, when multiple cities exceeded 30 μg/m3 during March. In Colombia, PM2.5 pollution is driven by a combination of local urban activity, household energy use, and significant regional transport. Within cities, vehicular exhaust, dust from unpaved roads, and industrial emissions are the primary contributors, while in rural areas, yiy Auasiiad saeao buey pue buyooo iot lo pue poom jo buung peaidsm aui background levels in both indoor and ambient air.96 Beyond local sources, PM2.5 levels sources such as the regular degassing of volcanos like Nevado del Ruiz, which contributes 7 μg/m3 of background PM2.5 through the atmospheric formation of sulfate aerosols.97 Additionall, northeast trade winds carry particulate matter from biomass burning in the Orincoco River Basin in Venezuela directly into Colombia, causing sharp season spikes in the Andean region during the dry season months spanning January through May.98 Bogota's bold clean air policies slashed air pollution by 24% since 2018, earning it the electric buses, building Latin America's largest cycle network, and restricting heavy freight. Annual hours spent at different PM2.5 pollution levels and planting 20,000 trees further improved equity and resilience, making Bogota a model for sustainable, healthier cities.