AbstractIncreased accuracy of weather forecasts does not necessarily increase commodity supply or farmer welfare. This study presents a stylized model of competitive production with rational expectations and demonstrates that improved weather information harms farmers facing an inelastic demand. Contrary to the conclusions of previous studies, the decline in farmer welfare does not require an expansion in expected supply. Better weather information may signal farmers to produce less on average under an inelastic demand. A supply decrease occurs when increases in the physical productivity of applied inputs are dominated by adverse price consequences.