Master of Agribusiness / Department of Agricultural Economics / Terry Griffin / Weather uncertainty plays a large role in farm management decisions. Changes in weather trends or increased variability during the growing season may alter the optimal farm management choices regarding machinery purchases, crop allocation to available acreage, varietal trait selection, and crop management practices. These farm management decisions impact the expected length of time available from planting to harvest. The dates that farmers most actively plant and harvest crops changes from year to year based on annual weather patterns that affect the number of days suitable to conduct fieldwork. This research analyzed corn planting and harvest progress, as well as the number of days suitable for fieldwork in Iowa, Kansas, and Missouri. Variability of days suitable for fieldwork across crop reporting districts within each state was reported. The total number of days suitable for fieldwork during the ‘most active’ planting and harvest weeks in each state were then analyzed to determine if increasing or decreasing trends exist and estimated as ordinary least squares (OLS) regression. The outcomes presented in this research indicated a statistically significant decreasing trend in days suitable for spring planting in Iowa, and positive trend in Missouri during fall harvest. However, no statistically significant trends were observed in Kansas for either time period. Farm management implications were examined in relation to the results of the days suitable for fieldwork analysis, specifically regarding machinery sizing decisions. Profit maximizing producers must manage machinery such that they are not over-equipped, but have adequate equipment capacity to plant and harvest all acreage within the available days suitable for fieldwork. Results of these analyses are directly of interest to farmers desiring to optimally equip their farms, agricultural lenders providing farmers with financing of equipment, and equipment manufacturers.