The concentrations of 89Sr, 90Sr, 137Cs, 210Pb, 212Po were measured in sequentially sampled rainwater during a thunderstorm occurring at Fayetteville, Arkansas, on January 29, 1981. Approximately concordant mean residence times ranging from 43 to 136 days were obtained from the observed ratios of 89Sr/90Sr and 210Pb/210Po ratio was found to correlate negatively with the 210Po/210Pb ratio. The variation of the 212Pb/210Pb ratio appeared to have resulted from turbulent mixing of the air masses, and it increased sharply after the rainfall reached a peak value.