Pollen was measured in ambient air by several methods and in wet atmospheric deposition samples at three monitoring sites in the National Atmospheric Deposition Program (NADP) National Trends Network. A method for counting pollen on filters was developed and provided pollen counts for NADP atmospheric wet-deposition samples and high-volume ambient air samplers (HVAS) for comparison with co-located traditional microscopy and PollenSense sensor counting methods during the 2021 pollen season. Air and precipitation samples were collected by the NADP and analyzed by the Wisconsin State Laboratory of Hygiene, in Madison, Wisconsin and Aerobiology Research Laboratories (Canada). Daily data were obtained from online summaries released by the National Allergy Bureau. Ten-minute records of pollen concentration measurements were obtained from the PollenSense network. Use of trade of firm names is for description purposes only and does not constitute endorsement by the U.S. government or the University of Wisconsin.