Receive retrospective ovulation estimates with Apple Watch Ultra
When worn to sleep each night, your Apple Watch Ultra can track temperature changes and use this data to help improve period predictions and provide retrospective ovulation estimates (not available in all regions*).
Important: The Cycle Tracking app should not be used as a form of birth control. Data from the Cycle Tracking app should not be used to diagnose a health condition.
Set up wrist temperature tracking
Set up Cycle Tracking and Sleep.
To establish a temperature baseline, ensure the Sleep Focus is on, then wear your Apple Watch Ultra while sleeping.
Wrist temperature data will be available after about five nights.
To view wrist temperature data, open the Health app on your iPhone, tap Browse, tap Body Measurements, then tap Wrist Temperature.
Retrospective ovulation estimates should be available after about two menstrual cycles of wearing your Apple Watch Ultra to sleep each night.
Note: Your body temperature naturally fluctuates, and can vary from night to night due to a number of variables. Wrist temperature can also be impacted by external factors like your sleep environment.
Turn off wrist temperature for Cycle Tracking
Open the Health app on your iPhone, tap Browse, then tap Cycle Tracking.
Scroll down, tap Options, then turn off Use Wrist Temperature.
If you turn off wrist temperature tracking, you’ll no longer receive retrospective ovulation estimates and wrist temperature data will not be used for period predictions.
For more information, see the Apple Support article Track your nightly wrist temperature changes with Apple Watch.