Reliable moisture measurement during drying is key to ensuring that grain is dried adequately to meet market requirements and be safe from spoilage by fungi in storage. While simple hand-held moisture meters are available for use by farmers in industrialized countries, smallholder farmers in developing countries cannot afford these devices and rely on subjective methods based on touch and feel to determine grain moisture. In this study, a simple, low-cost method to determine whether maize is dry enough for storage was developed based on the use of an affordable hygrometer and EMC/ERH relationship for maize. The Mini Digital hygrometer, the lowest cost hygrometer of 5 types tested, was the best based on its accuracy, device-to-device variability and ability to clearly distinguish various moistures of maize. A simple illustrated information-card was developed to guide farmers on using the device and for testing its accuracy.