A climatology of soil moisture in the 6- to 12-in. layer beneath the surface of the earth is required for estimating the probability of favorable trafficability conditions. Insufficient measurements are available to prepare such a climatology. Therefore, this study was undertaken to determine the feasibility of estimating soil moisture from long records of meteorological observations, and then using the estimates to obtain the desired climatology. It was found that the meteorological observations contained insufficient information to accurately estimate day-to-day changes in soil moisture. However, they contained sufficient information to delineate the dry and wet seasons and to identify the periods and rates of transition from one season to the other. (Modified author abstract).