Samsung is finally making the Galaxy Watch 5 use a temperature sensor.

The Samsung Galaxy Watch 5 shares mostly the same internals with the Watch 4 with some minor tweaks. As for the Pro model, it carries the same internals, albeit in a rugged chassis that can take on any terrain possible. And thanks to the larger chassis, it also packs a bigger battery to deliver multi-day battery life. Both these smartwatches also pack an IR-based temperature sensor, but it has remained inactive so far. Eight months after the Galaxy Watch 5 series went on sale, Samsung is finally working on a wearable temperature sensor, but it might not work for you.

Samsung is enabling the Galaxy Watch 5’s temperature sensor for better cycle tracking. Since the menstrual cycle affects the basal body temperature, it helps women to accurately predict their next period. The smartwatch’s temperature sensor automatically records your basal body temperature every day and tracks skin temperature changes to provide a more accurate estimate of when your next period will start.

The Korean giant has partnered with Natural Cycles to develop a cycle tracking feature in Samsung Health. It first announced this partnership in February 2023. Why is there a delay in activating the temperature sensor? Before Samsung could offer skin-based temperature monitoring, it had to get regulatory approval from Korea’s MFDS, FDA in the US and Europe. It was a similar story when the company initially added ECG capabilities to the Galaxy Watch lineup.

Apple Watch Series 8 and Apple Watch Ultra use the built-in temperature sensor to provide more accurate menstrual cycle predictions.

The temperature-based cycle tracking feature will launch in Korea, the US and 30 European countries with the Samsung Health update starting today. Once you receive the update, you can activate the feature by enabling cycle tracking in Samsung Health and enabling this. Predict time with skin temperature Option in settings. For privacy, Samsung encrypts all data stored on your device.