Regional assessments are critical to evaluate resources at risk from disturbances, such as acidic deposition, which occur in large spatial extent. It is imperative to accurately quantify atmospheric deposition to the regions like the Adirondack Mountains of New York where soils and surface waters are highly sensitive to inputs of strong acids. Spatial patterns in precipitation quantity and concentrations of major ions in precipitation in the Adirondack region were estimated based on the locations of monitoring sites using the data from 1988 to 1999. Mean monthly minimum and maximum daily air temperatures were also predicted to characterize site conditions. The trends in precipitation quantity, temperature, and most ion concentrations during the period examined were not significant or minimally significant, suggesting that the mean values over the period could be used for the regression models to describe spatial patterns. The spatial variations in the mean annual and monthly precipitation amounts, monthly mean minimum and maximum daily temperatures, and annual and quarterly sulfate and nitrate concentrations were generally explained by the regression models. Comparisons with the regression models of Ollinger et al. (US Ecological Applications 3(3) (1993) 459; US Department of Agriculture, Forest Service, Radnor, PA., 1995, 30p.) for the northeastern US suggest local variations in climate variables for the smaller Adirondack region. Further, precipitation quantity, minimum and maximum temperatures, and concentrations and deposition of ions in precipitation were predicted for the entire Adirondack region, using digital elevation models among others. Precipitation quantity and the sulfate and nitrate concentrations generally increased from the northeast to the southwest. Precipitation quantity and sulfate concentrations also generally increased with elevation. Minimum and maximum temperatures decreased from the southeast to the northwest and with elevation.