Answer: The temperature ideal for sleep will vary from person to person,Apart from temperature Humidity, Air movement/ breezetoo plays a role. So there is no simple answer.I love to sleep in summer with an AC setting of23-24 Celsius.For the Non summer months in mumbai a room with good breeze is idealIt depends on the person. i need it cooler than my mom and sister because my regular body temperature is much lower (95.5-96.0 on average), and what's a nice temperature for them is wayyyy too hot for me. they like it about 70*F, i like 55 to 60*F.