CircadiaOSShort answer: program four setpoints instead of one. Cool the room as you fall asleep, drop to your lowest setting for deep sleep, warm it slightly in late night, and bring it up a couple more degrees before your alarm. On most Wi-Fi thermostats this takes about ten minutes. CircadiaOS does it automatically every night.
Why a single nighttime temperature is wrong
Your body does not hold one temperature overnight. Core temperature drops as you fall asleep, reaches its lowest point during deep sleep in the first half of the night, then climbs gradually toward morning. A bedroom locked at 68°F all night is too warm when you need to cool down and still too warm when the body is ready to rise. A bedroom locked at 63°F helps you fall asleep but leaves you shivering at 4 a.m.
The fix is straightforward: match the room to the body. That means a schedule with at least four phases, not one flat hold. The research behind the ideal range.
The four-phase approach
Think of the night in four blocks. Each one has a job, and each one calls for a different temperature.
- Pre-sleep (bedtime to about 30 minutes in). Cool the room to roughly 66–67°F. This helps your core temperature start dropping without making the bed feel cold when you climb in.
- Early night (deep sleep window). Drop to 63–65°F. Deep sleep is concentrated in the first three to four hours, and a cooler room supports the core temperature trough your body needs to stay there.
- Late night. Raise to about 65–66°F. Deep sleep tapers off and lighter stages dominate. A slightly warmer room keeps you from waking up cold as your body's own temperature begins to rise.
- Pre-wake (45–60 minutes before alarm). Bring it up to 67–68°F. The gentle warm-up aligns with the cortisol rise that naturally nudges you toward waking, and it makes getting out of bed less jarring.
These are starting points, not prescriptions. If you run hot, shift the whole curve down a couple of degrees. If you are over 60, the late-night and pre-wake phases often work better a degree warmer. Settings for hot sleepers.
How to program it on popular thermostats
ecobee
ecobee has a built-in "Sleep" comfort setting, but it is one temperature, not a curve. To build a four-phase schedule, create a custom schedule with multiple comfort settings or use the ecobee app's scheduling screen to add four time blocks overnight. Set each block's target temperature to match the phases above. The main limitation is that ecobee comfort settings are broad, so fine-grained overnight changes require manually adding multiple transitions. Full ecobee sleep guide.
Google Nest
In the Nest app, go to the thermostat's schedule and add temperature points for each phase. Nest lets you place setpoints at specific times, so you can add four entries across the night. If you use Nest's "Sleep" preset in the home/away routine, that only sets one temperature when you go to bed. To get a curve, skip the preset and place the setpoints directly. Full Nest sleep guide.
Honeywell Home
The Honeywell Home app supports time-based scheduling. Add four periods to your overnight schedule, each with the target temperature for that phase. Most Honeywell Home Wi-Fi models (T9, T10 Pro, Lyric) support enough daily schedule slots to handle the four transitions without running out.
The catch with doing it manually
Manual programming works, but it has a real cost. If your bedtime shifts by 30 minutes, the schedule is wrong. If you travel for a few days and come back jet-lagged, the schedule is wrong. If you want to test whether 64°F or 63°F works better in early night, you have to remember to change it, track the results yourself, and change it back if it does not help. Most people set it once and never touch it again, which means it slowly drifts from useful to ignored.
Or let CircadiaOS handle it
CircadiaOS connects to the smart thermostat you already own and sends a four-phase schedule every evening. It builds the starting curve from your age and sleep window, then adjusts it nightly as your bedtime shifts. On Premium, it reads your wearable data from Oura, Whoop, Apple Watch, Garmin or Fitbit and runs one-variable-at-a-time experiments, changing a single setpoint, holding it for one to two weeks, and keeping only the change your sleep data supports. No manual reprogramming. How the method works.
Questions
What is the best thermostat schedule for sleep?
A four-phase schedule that cools the room as you fall asleep (around 66–67°F), drops lower for deep sleep (63–65°F), warms slightly in late night (65–66°F), and rises before your alarm (67–68°F). The exact numbers depend on your body. CircadiaOS builds and adjusts this schedule automatically.
Should I change my thermostat temperature during the night?
Yes. Your body's temperature changes overnight, dropping for deep sleep and rising toward morning. A room that follows that curve supports better sleep than one held at a single number all night.
Does CircadiaOS work with my thermostat?
CircadiaOS works with ecobee, Google Nest, Honeywell Home, Sensi and 15+ other Wi-Fi smart thermostats. Check the full list.
Can I use CircadiaOS without a wearable?
Yes. The Free plan builds a starting schedule from your age and sleep window with no wearable required. A wearable unlocks personalization on Premium, where CircadiaOS uses your sleep data to refine the schedule over time.
Related guides
- Best temperature for sleep — the research behind 60–67°F and why the answer is a curve.
- ecobee sleep mode — what ecobee's built-in sleep setting does and how to go further.
- Nest thermostat sleep settings — how to build an overnight schedule on Google Nest.