Like Nam said it can vary , as a general rule of thumb indicas can deal with cooler temps and sativas are better with warmer temps, which leaves hybrids floating around in the middle and their ability to deal with heat/cool come down to the percentage of the parental genetics making up the strain.
The happy medium is around 25C/77F and it is generally accepted not to go more than 5C/9F above or below that.
It is possible to go above 30C/85F if you have high light level in conjunction with CO2.
My cab is LED and temps are between 24C/75.2F & 28C/82.4F depending on the ambient temps of the day.