I do not have access to the specific details regarding the weather conditions of Gorenja Vas Tuff or the type of application you are referring to. However, in general, tuff stones are volcanic rocks that can be porous and may absorb moisture, which could make them less suitable for exterior applications in areas with high levels of precipitation or in very sunny and dry climates where the stone could be prone to cracking. However, the best way to determine if Gorenja Vas Tuff is suitable for your specific project and climate conditions would be to consult with a qualified stonemason or building professional.