The purpose of this study was to evaluate the effect of three conditions of temperature and humidity on pesticide penetration through the fabric. Two fabrics were used, a 100% cotton and a 50/50 cotton/polyester. The three conditions used were 29°C (85°F) with 75% relative humidity (RH), 22°C (72°F) with 65% RH, and 18°C (65°F) with 55% RH. The application of Dicofol pesticide was completed using an enclosed spray chamber that simulated actual field conditions encountered during air blast spraying. Fabric type had a greater influence on pesticide penetration than atmospheric conditions. Consistent standard laboratory conditions of 21.1°C (70°F) with 65% RH are recommended for use in future laboratory penetration tests.