Synopsis: Maximum daily temperatures and rainfall averaged by 5‐day periods for 18 periods during each growing season of a 38 year span were related to corn yields at Experiment, Georgia, using a set of second‐degree orthogonal polynomials as regression integrals. Results indicated that high temperatures near the end of the growing season are beneficial if rainfall is adequate. High temperatures when no rainfall occurs causes greatest damage in the first half of June. The value of an inch of rainfall declines for a time after the usual planting date and then increases sharply during the later part of the growing season, especially when associated with the higher temperatures which are normal for that period.