Higher humidity, which is predicted for northern latitudes, can cause significant changes in forest growth and function. Increase in air humidity at FAHM experimental site, Estonia, has shown to affect tree water status and increases the levels of antioxidants and accumulation of carbohydrates in leaves. This datasets provides data of VOC and NOX emissions of Silver Birches from summer 2019 from three control plots and three plots with increased air humidity. Data of leaf water potential, xylem flux density and leaf osmotic potential are provided as well.