The influence of dew on atmospheric composition is poorly understood. Results from this work show that dew can uptake a significant fraction (roughly two-thirds) of boundary layer gas-phase ammonia. Furthermore, an average of 95 % of the ammonia sequestered in dew is released back to the atmosphere the following morning during dew evaporation. Dew has the ability to affect air quality and N-deposition and should be considered when modelling ammonia concentrations, as well as other soluble gases.