Technical Abstract: In most years, peanuts from the south-central US have excellent soluble sugar levels for the food industry; however, in some growing seasons high sugar contents are a significant problem associated with roasted color variation. To test the hypothesis that high sugar content was related to low temperature extremes, this study evaluated temperature effects on carbohydrate levels in peanuts grown hydroponically. Peanuts were grown with separate pod and shoot-root zone day/night temperatures. Peanut carbohydrate contents were evaluated in seed from pods grown at nighttime root-zone temperatures of 15C, 20C, 22C, 24C and 28C. Total carbohydrates were higher in peanuts grown in 125C root-zone temperatures compared with those maintained at 28C. Peanuts harvested at 120 days after planting (DAP) had the highest sucrose contents at 15C and 20C, the second highest sucrose contents at 22C, and the lowest sucrose content at 24C. The temperature-induced differential in sucrose contents of 120 DAP peanuts was not observed in peanuts harvested at 141 DAP. These findings support the observation that soil temperature has a greater impact on peanut carbohydrate accumulation than air temperature. The results also suggest that nighttime soil temperatures of 15C will result in more mature peanuts if they are grown for 141 days after planting; however, harvesting before the peanuts reach maturity may result in elevated sugar contents.