"Provide your boa constrictor with a basking spot of 88-90°F and an ambient (background) temperature of 78-80 °F. The ambient temperature should not fall below 75 °F. It is vitally important to KNOW the temperatures at which you are keeping your snake(s). DO NOT GUESS!!
It is important to note that common boas, while very hardy snakes, are sometimes less tolerant of sub optimal temperatures, especially when subjected to them for extended periods of time. Improper temperatures can lead to regurgitation, respiratory infections, stress on your boa's immune system & consequently, death."
That a direct cut and paste from the columbian boa caresheet on this forum a far as temps go. Humidity is basically just like a ball python....50-60% normally, 70% during the shed cycle (from the moment you notice a pink belly until the shed is complete).
~~Jo~~