Abstract
The present dataset contains three years of continuous, high-frequency air-quality monitoring of particulate matter (PM2.5 and PM10) in the metropolitan area of Asunción and the Western Region of Paraguay. Data were collected from eleven monitoring stations: nine in urban Asunción, one at the National University of Asunción campus in San Lorenzo, and one in the semi-rural Cerrito, Paraguayan Chaco. The monitoring period covers from April 2019 to December 2021. The monitoring network was established to record spatio-temporal variations in particulate matter concentrations throughout urban and semi-rural environments. Key meteorological variables, including temperature, relative humidity, atmospheric pressure, and wind direction, were continuously recorded to enable analysis of dispersion trends. Particulate matter concentrations were measured at five-minute intervals using Optical Particle Counters (OPC-N2), with data automatically transmitted to a central server every thirty minutes for quality control, storage, and processing. This dataset allows direct comparison with national air-quality standards established by the National Resolution No 259/2015 of the Ministry of Environment and Sustainable Development. Its full coverage supports policy evaluation, cross-sector assessments, and studies on environmental and public health impacts. Full technical documentation is included to secure transparency, traceability, and reproducibility, providing the basis for management and scientific research in Paraguay.