June runoff in the Missouri River Basin above Sioux City, Iowa was 3.3 million acre-feet, 60% of average. The updated 2025 calendar year runoff forecast for the Missouri River Basin above Sioux City, Iowa, is 19.1 MAF, 74% of average, and slightly lower than last month’s forecast. The runoff forecast is based on current soil moisture conditions, mountain snowpack, and long-term precipitation and temperature outlooks.