On Apple Watch Series 8+ and Ultra and watchOS 9+, Apple finally offers temperature sensing, so you can now track your skin and body temperature from your wrist.
Tracking your temperature from your wrist is especially useful for women who track their ovulation and are trying to get pregnant or if you experience feverish symptoms that might indicate the onset of an illness or other health condition.
- Best Apple Watch apps for tracking your period or ovulation
- Wearables and Body Temperature Monitoring – current products and what to expect in the future
- Apple’s new patent details elements of the rumored body temperature sensor
How to set up your Apple Watch to track your temperature
First of all, this feature is only available for Series 8 and above watches and the Apple Watch Ultra models. It is not available for any other Apple Watch model, even if that watch runs watchOS 9 and above.
Apple designed a different way to sense a person’s temperature using two unique sensors instead of one!
One sensor is on the back of the watch, so it’s nearest to your skin, and the other is just under the display, which helps reduce the influence of your outside environment.
To get temperature information, you need to wear your watch to bed.
The watch currently tracks changes in your wrist temperature only when you sleep. It does not track daytime temperature when you are active.
Establish your personal baseline temperature using the Sleep app
Every person’s normal body and skin temperature are different.
So it’s important to establish your temperature baseline by wearing your Apple Watch to bed using Apple’s Sleep app with Sleep Tracking turned on for five successive nights.
With Sleep tracking on, your watch measures your wrist temperature every five seconds when you go to bed and fall asleep.
Like other sleep metrics, tracking your temperature is a passive process that occurs in the background–you don’t need to do anything other than using the Sleep app and turn on sleep tracking.
Once you complete five nights, you should see your Wrist temperature data in your iPhone’s Health app.
Turn on Sleep Tracking on your Apple Watch
- Open the Settings app and choose Sleep.
- Scroll down and toggle on Sleep Tracking. Once you turn on Sleep Tracking, your Apple Watch tracks your sleep and adds sleep data, including your wrist temperature, to the Health app on your iPhone.
- Open the Sleep app and if you haven’t already, set up your Bedtime and Wake up schedules.
- You can also turn on a Sleep Focus in your watch’s or paired iPhone’s Control Center’s Do Not Disturb options before you go to bed.
- Make sure you also turn off your Sleep Focus in the morning by opening Control Center and tapping the bed icon.
- Make sure you use the Sleep Focus for at least 4 hours a night for 5 nights to get accurate wrist temperature data.
You can also change these sleep tracking and sleep focus options on your iPhone via the Apple Watch app by tapping My Watch> Sleep and toggling on Track Sleep with Apple Watch.
To update a sleep focus, tap Manage Sleep Focus in Settings.
Review your body and skin temperature details in the iPhone Health app
- Open the Health app on your iPhone, then tap the Browse tab.
- Tap Body Measurements and choose Wrist Temperature.
- Tap a point inside the chart to see more details from a moment in time or a deviation from your baseline. Changes in your baseline temperature can indicate things like illness, increased exercise, jetlag, or even changes due to menopause.
How to turn off Wrist Temperature
If you don’t want your watch to record your temperature while sleeping, you can turn off this measurement and still track your sleep.
- On your iPhone, open the Watch app.
- Tap Privacy and turn off Wrist Temperature.
An Apple Watch Series 8+ or Apple Watch Ultra can also use your wrist temperature information to estimate the likely day of ovulation after it has occurred to help you get a better understanding of your body’s ovulation cycle.
Your Apple Watch uses your wrist temperature data to detect an increase in your body temperature that often occurs after ovulation (called the biphasic shift.)
Apple’s algorithms use that wrist temperature data and logged cycle data to estimate the day ovulation likely occurred.
To track ovulation, you use the Cycle Tracking app. This app then uses the temperature information from the Sleep app to provide retrospective ovulation estimates.
Additionally, Cycle Tracking can send notifications if a person’s logged cycle history shows a possible deviation, including things like irregular, infrequent, prolonged periods, or persistent spotting. All of these symptoms can indicate an underlying health condition.
How to track your ovulation cycle using Apple Watch
- Set up Cycle Tracking and turn on fertility predictions and notifications. Also, ensure you do not have a log of any ongoing cycle factors.
- Set up sleep tracking on your Apple Watch and make sure you use a schedule or manually turn on your Sleep Focus.
- Sleep with your Sleep Focus turned on for at least 4 hours a night for 5 consecutive nights, so your watch provides accurate wrist temperature data.
- Wear your new watch and track your period for at least 2 cycles to receive your first ovulation estimate. It takes about 2 menstrual cycles of wearing an Apple Watch to sleep each night with Sleep Focus enabled for ovulation estimates to be available.
- To track your cycle from your Apple Watch, open the Cycle Tracking app, swipe to the correct date, then tap the oval to log your period.
- To track in the iPhone Health app, select Browse > Cycle Tracking. Swipe to the correct day, then tap the oval to log your period.
How to review your ovulation estimates
- Wait for a notification from the Cycle Tracking app that an estimate of when you likely ovulated is available. YOu get your first notification after 2 menstrual cycles.
- Open the Health app on your iPhone or the Cycle Tracking app on your Apple Watch.
- In the top graph, look for your ovulation estimate in your fertile window.
- A light purple oval marks your retrospectively-estimated ovulation day. And the light blue oval marks your predicted six-day fertile window.