Cotton moisture absorption and desorption rates at temperatures ranging from 5 to 53 C were studied. The moisture data was found to fit a theoretical, exponential decay function. The coefficients in the theoretical equation were fit to the experimental data using nonlinear regression analysis. Temperature and air type (dry or humid) significantly affected the diffusivity (rate) and the shape parameters in the nonlinear equations. The rate of moisture transfer increased with low humidity air and with increasing temperature for the range of 5-41 C and then decreased for the high temperature (51-53 C) runs.