Vandas are found in hot and humid climates. They are the quintessential tropical plant. Unlike a lot of orchids, vandas want direct sunlight and lots of it. They do not like to be crowded together and do not like to be disturbed once established.
Today, most of the Vanda orchids available for sale in the United States have come from Thailand, Singapore or South Florida. These areas offer the perfect humidity and temperature ranges for Vandas to become robust and happy flowering plants. Vandas will grow best in temperatures ranging up to 105 F to no lower than 55 F. Anything less than 55 degrees will not only discourage the plant from growing, it will damage it.
Hanging your Vanda orchid outside in the summer will help it build up the energy to bloom. Vandas love direct sunlight, and will appreciate it to the point of burning. If the leaves show yellowing or splotches, that is sunburn and you must move the orchid to a more protected area. Bring the Vanda inside before there is any chance that the night temperatures will dip below 55 F.