Geocarposphere (GCS) temperature was correlated to yield, grade, jumbos (outturns), aflatoxin, and germination of Florunner peanuts grown in Southwest Georgia during CY 1981–1987. Maximum daily GCS temperatures usually provided better correlations with yield and quality factors than minimum and mean daily GCS temperatures. Maximum daily GCS temperatures were also more indicative of plant stress. Minimum GCS temperatures were important for rapid emergence, root growth, and maturation. Both maximum and minimum daily GCS temperatures were important for reducing impact by wet and dry weather pests. Maximum yield and quality will be produced when production practices are managed to maintain GCS temperature in the range of 20–35 C (68–95 F) at planting time, 20–31 C (68–87 F) prior to and during the early part of fruiting, 21–28 C (70–83 F) during primary pod addition and 21–29 C (70–85 F) during primary pod maturation period. However, maximum GCS temperatures below 27 C (80 F) should be avoided to minimize impact of wet weather pests. This and other information that relate scouting data and field history to yield and quality have proven useful in developing an Expert System and models for managing peanut production and marketing.