Orchids are extremely tolerant of temperature ranges.
Here in Florida I grow all my Orchids outdoors. Temperatures range from the low 30s, for short periods during Winter nights, to over 100, for extended periods during the Summer.
We may get leaf damage during the extremes but lose only a small percentage of plants. When the temperatures drop below 60 degrees for extended periods, Orchids will slow its growth and hibernate.
Orchids have been on the earth since the time of the dinosaurs surviving without us. They do badly when we try to force growing with water and fertilizers during a time when they can not use it.
Too much water during slow growing periods leads to root rot. When the temperatures cool and the plants stop growing reduce water and almost stop fertilizer.
While Orchids can survive a wide range the best growing conditions are the same temperatures in which we like to live 60-80. Remember all general statements like these have exceptions.
Orchids that grow in the mountains will like a cooler range. Others will do badly in the cold range. Whenever an orchid has special conditions, our Orchid page will list the care necessary and the reason.
Growing Orchids is easy, but forcing an Orchid to grow in conditions that is not natural is very stressful. If you are not sure if an Orchid would be good for you fell free to ask first.