Yes, Karaja Grey Sintered Stone can be used for exterior applications in very sunny climates. Sintered stone is a highly durable and resistant material that is suitable for outdoor use. It is resistant to UV rays and fading, making it an excellent choice for areas with intense sunlight. Additionally, sintered stone is also resistant to extreme temperatures, making it suitable for hot climates. However, it is always recommended to consult with the manufacturer or a professional to ensure the specific products suitability for your intended use.