This M.Sc. Thesis focuses on the analysis of pollen grains concentration and the identification of pollen seasons in Warsaw using in-situ measurements, optical microscopy, and remote sensing. Pollen grains play a crucial role in both human health and atmospheric processes. These grains vary in size and shape, with their distribution in the atmosphere as influenced by meteorological factors. This thesis investigates the pollen concentration in Warsaw during 2023. Twenty pollen taxa were identified by analyzing 297 days of in-situ measurements, and 20 pollen type-dependent seasons were defined. The results indicate a prolonged pollen season compared to previous years, potentially due to climate change. Additionally, the study explores the transition from tree pollen to grass and herb pollen that occurred during late May and early June 2023, providing insights into vegetative shifts influenced by weather patterns. The relationship between pollen size and concentration was examined, revealing that larger pollen particles were dominant during the first five days of the analysis. To complement the pollen analysis, data on PM10 and PM2.5 concentrations were used from a nearby monitoring station with a background similar to the Warsaw Observatory Station (WOS). A fine-to-coarse ratio was used to analyze the particle size, and the data showed a strong correlation between larger particle sizes and higher pollen concentrations, during the selected period. The study also highlights the importance of synergizing in-situ and remote sensing measurements, using lidar to identify pollen layers within the atmospheric boundary layer. The findings emphasize the significance of pollen in both health impacts and atmospheric dynamics, including its role in cloud formation and potential contribution to drought through cloud condensation nuclei (CCN) processes.