Yes, Indias Raja Red Slate can be used for exterior applications in very humid climates. Raja Red Slate is a durable and weather-resistant natural stone that can withstand high humidity levels. It is commonly used as a paving material for outdoor pathways, driveways, and patios in various climates, including humid regions. However, proper installation techniques and regular maintenance are essential to ensure its longevity and prevent any potential damage due to moisture and humidity.