These data include the aggregated childhood pneumonia cases by district, which were obtained from the epidemiological surveillance system of the Ministry of Health (MINSA), which integrates information from all health centers in each district. Additionally, the data include the weekly PM₂.₅ concentrations that were retrieved from open data provided by the National Service of Meteorology and Hydrology of Peru (SENAMHI), which conducts environmental monitoring through sentinel stations located in each district included in the study. Exposure was operationalized using the weekly median PM₂.₅ concentration expressed in µg/m³.