Phalaenopsis required a fairly warm climate. The ideal night temperature is 15 to 18 degrees celcius and daytime temperature range of 21 to 27 degrees celcius. Since this temperature range is similar to that of many homes, it makes an ideal house plant.
35.0 Celsius is the maximum day temperature.
Temperatures close to the window on a windowsill will be colder or hotter than your general house temperature. Occasional deviations will not harm your plant, except when it is in bud – chilly temperatures may cause the plant to stop budding. Fluctuating temperatures can cause bud drop on plants with buds ready to open.