Soaking rainfall returned across much of the Midwest, stalling most fieldwork. Some of the heaviest rain, 2 to 4 inches or more, fell in upper Midwestern States that had planted one-quarter to one-half of their corn and soybeans the previous week, from May 8-14. In the lower Midwest, several days of warm, dry weather provided a brief fieldwork window. In fact, weekly temperatures generally averaged 5 to 10°F above normal from the middle Mississippi Valley to the Atlantic Seaboard.
From May 17-19, a short-lived heat wave along the Atlantic Seaboard pushed temperatures to 90°F or higher. In contrast, a late-week cool spell resulted in some patchy freezes across the northwestern half of the Plains. Temperatures averaged at least 5°F below normal across large sections of the northern High Plains and the West.