The NARSTO_EPA_SS_HOUSTON_DMA_DATA measurements consist of aerosol size distributions and number concentrations collected in Houston, Texas, beginning in August 2000 and ending in November 2001. Data were collected at two sites throughout this period (Aldine and HRM3), and a third instrument sampled at two sites (La Porte: Aug-Sep 2000; Deer Park: Sep 2000-Oct 2001). These measurements were collected as part of the EPA Supersite program. High-flow differential mobility analyzers (DMAs) were used to collect these data.The Houston Supersite is one of several Supersites that was established in urban areas within the United States by the U.S. Environmental Protection Agency (EPA) to better understand the measurement, sources, and health effects of suspended particulate matter (PM). The overall goals were to characterize the composition and identify the sources of particulate matter in Southeastern Texas, to develop and test new methods for characterizing fine particulate matter, and to collect data on the physical and chemical characterization of fine particulate matter that can be used to support exposure and health effects studies.NARSTO (formerly North American Research Strategy for Tropospheric Ozone) is a public/private partnership, whose membership spans government, the utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission is to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; activities provide input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are available.