Chemical composition of precipitation in Albany, NY from July 1986 to December 1988 has been studied. Mean volume-weighted concentrations (μeqℓ-1) were: acidity, 104.0; alkalinity, -63.7; SO42-, 52.8; NO3-, 29.8; Cl-, 5.6; F-, 0.50; NH4+, 19.3; Ca2+, 6.5; Mg2+, 2.8; Na+, 3.5; and K+, 1.4. Mean pH was 4.2 . Seasonal patterns were pronounced for most species. Concentrations of H+, SO42-, NO3-, NH4+ and Ca2+ peaked in the summer and spring. Deposition was related to rainfall amount by a power law relationship in which the exponent of the equation was ∮.6. Wet SO42- deposition was 2.35 keq ha-1 over a 30-month period. The SO42- and NO3- deposition rates observed at Albany indicate that transport from midwestern sources have a major influence at this site. On the average, free H+ ion concentrations determined from pH measurements accounted for 51% of the measured total acidity. There were unknown species, most likely organic acids, that could contribute to the acidity. Correlation and regression analyses indicated that major anions, SO42- and NO3-, were closely associated with H+ and NH4+ ions. Factor analysis revealed four common factors which are related to fossil-fuel combustion, sea spray, cement factory and biomass burning. © 1990.