Yes, Quy Nhon Red Granite from Vietnam can be used for exterior applications in very rainy climates. Granite is known for its durability and ability to withstand harsh weather conditions, including heavy rainfall. It is resistant to water absorption and has good resistance to staining, cracking, and fading. However, it is always advisable to consult with a professional stone supplier or installer to ensure the suitability of the specific granite type for the intended use and local climate conditions. Additionally, proper installation and regular maintenance, such as sealing the stone, will help enhance its longevity and performance in rainy climates.