We compiled criteria pollutants from four air quality monitoring stations in Bogotá, eight in Santiago, and five in São Paulo to characterize the impact of emission changes on air quality during the early Coronavirus-imposed lockdown. Time series include hourly measurements (UTC) of ozone (ppbv), nitric oxide (ppbv), nitrogen dioxide (ppbv), carbon monoxide (ppmv), and PM2.5 (microgram per cubic meter), from 1 January 2014 to 1 June 2020.Specifically, datasets were used to compare the lockdown period (March-May 2020) with the baseline period defined as the multi-year average between 2014 and 2019.Santiago air quality data were downloaded from the website of the official monitoring network (https://sinca.mma.gob.cl). The data provided correspond to the following stations: Cerro Navia, El Bosque, Independencia, La Florida, Las Condes, Parque O'Higgins, Pudahuel, and Puente Alto.