Bedroom Temperature
topic
Optimal bedroom temperature for sleep is 18–19°C (65–67°F) — the range that facilitates the core body temperature drop of 1–2°C required for sleep initiation and slow-wave sleep maintenance — with temperatures above 21°C measurably reducing slow-wave sleep, increasing arousals, and producing the subjective experience of lighter, less restorative sleep. The optimal temperature range facilitates heat loss through the skin, accelerating the physiological thermoregulatory process that signals sleep readiness.
Role
Bedroom temperature is the most impactful single environmental variable for sleep quality and among the most commonly ignored. The majority of people sleep in bedrooms at 21–23°C — the comfortable waking room temperature — without awareness that this temperature is actively preventing the thermoregulatory process required for deep sleep. Reducing bedroom temperature by 4–5°C from the typical indoor default is one of the most consistently reported high-impact sleep improvements available, requiring no other behavioral change, no supplements, and no devices.