Seasonal analysis was used to identify historical seasonal patterns for cotton cash and futures prices, consumption, exports, and stocks. Memphis and Lubbock monthly cash prices displayed significant seasonality and increased volatility during recent years. Strengthening seasonal patterns and volatility were found in both cash and cotton futures price series. All the futures contracts displayed traces of seasonality, and increased volatility and "maturity effect" after the cotton policy changes in 1985. Seasonality was evident for consumption, exports and stocks.