Apple updated its Apple Watch line on Sept. 7 with the expected Apple Watch Series 8 and SE models that are decent (but not earth-shattering) upgrades over last year’s models.

The Apple Watch Series 8 breaks new ground with skin temperature readings, women’s health tracking, new motion sensors, increased battery life and international roaming for cellular models. Here’s what you need to know about the latest Apple Watches — and where you can get your hands on one.

Where to preorder the Apple Watch Series 8 and SE

The Apple Watch Series 8 and Apple Watch SE are available to order on the Apple Store now. The Series 8 starts at $399 for the GPS version and $499 for the cellular version, and the SE starts at $249 for the GPS version and $299 for cellular. Both will begin shipping on Sept. 16. Both watches include three months free with Apple Fitness+.

• Apple Watch Series 8 (from $399 at Apple)
• Apple Watch SE (from $249 at Apple)

Major updates for women’s health, overall safety and battery life

Apple says the two temp sensors — one on the underside for the skin and one on the top for air temp — allow for precise body temp readings to within 0.1 degree Celsius. Wearing the watch at night will detect biphasic shifts, often an indicator of hormone shifts and ovulation. The company says all this data allows your watch to estimate your ovulation date retroactively. That’s a big deal for family planning.

Women have been able to track menstrual cycles on Apple Watches for some time now, but this is the first time that Apple has allowed for an estimated ovulation date. Several apps are available for doing so already, but given the current politics of reproductive health in the United States, some women have had privacy concerns about that data being stored on servers.

Apple is sensitive to those concerns. The company says women’s cycle data will be encrypted on the watch itself and only accessible via a passcode, Face ID or Touch ID. If you sync to iCloud, it will use end-to-end data encryption. Apple stressed that no one but you will be able to unlock the data.

Other new sensors include a beefed-up accelerometer, barometer and microphone that Apple says can detect car crashes. If it detects a sudden change in velocity (up to 256 gees), air pressure (from airbag inflation) and the sound of a crash, it will offer to call 911, send your location and call your emergency contacts. This is a natural evolution of the Apple Watch’s fall detection.

And, hallelujah, the Apple Watch now has increased battery life. Apple says the new Series 8 (starting at $399 for GPS and $499 for cellular) and SE ($249/$299) will get 18 hours on a full charge — and, thanks to a new low power mode, up to 36 hours of battery life. The new low power mode is more capable than the current low power mode, which turns off almost everything. The new mode uses new battery-squeezing algorithms that turn off only the most power-hungry functions, such as the always-on display and the autodetection of workouts.

Finally, the Apple Watch Series 8 cellular models include international data roaming (for free or at a low price, Apple claims), making it more useful now that people are traveling internationally again.

The SE model offers much of the same as the Series 8, except for the temp sensors, blood oxygen, electrocardiogram reading and always-on display. It’s also a hair smaller (44mm and 40mm faces compared to the Series 8’s 45mm and 41mm).

Except for the women’s health features, the Series 8 and the SE aren’t huge upgrades over the Apple Watch Series 7 or the 2020 Apple Watch SE. The new watchOS 9 offers many new features, but they will extend to several previous models, so you’ll get about 90% of the new functionality anyway.

But these are good upgrades if you’re a first-time smartwatch shopper or if you have an Apple Watch Series 4 or earlier. The SE is a great starter watch for kids or people who don’t need quite so much health data. The Series 8’s women’s health features look great for people looking to take control of their reproductive health while also maintaining their privacy.