By comparing deposition of nitrate in successive hours of precipitation samples taken over a six year period at Brookhaven National Laboratory (BNL) Long Island, New York, we have estimated scavenging coefficients in air, λ, for nitrate under a variety of meteorological and seasonal conditions. The square root transformation of the scavenging coefficients λ1/2 yields an approximately normal distribution; the mean value is 1.1¿10-4 s-1, in general agreement with previous experimental and theoretical estimates. An interesting property of the distribution of the scavenging coefficients is that the ratio of the mean value of λ1/2 to its standard deviation varies little from 2.4 for various subsets of data; this property may limit the choice of stochastic models which describe the scavenging process. A trend analysis of the relationship between scavenging coefficients and rainfall rate indicates that the scavenging coefficient of nitrate does not increase for rainfall rates ≤3.2 mm h-1. The indicated increase at greater rainfall rates is qualitatively similar to model predictions but is based upon a small number of data points. The mean scavenging coefficient for winter rain events is greater than for sno