The 1988 drought renewed interest in the relationship between weather and yields. Regression equations are estimated for U.S. average corn yields. Results illustrate that there is little carryover effect from a drought to yields in the following year—yields tend to rebound to near trend levels following a drought. Soil moisture recharge is an important consideration, but too much moisture in the spring can delay plantings, which typically reduces yields by exposing more of the critical growing stages of the crop to less favorable summer weather. The most important factor in determining corn yields in the year following a drought is weather during the growing season. Timely rains in July are the most critical, with July temperatures next in importance in most years. Other results show that average weather in not necessarily optimal for yields, and that there are more downward risks in yield responses to weather than there is upward yield potential.