Does the Xiaomi Watch S3 support viewing altitude air pressure?

Support.
You can view it by the following steps:
Tap the [Air pressure] icon on the application list interface to display the current air pressure value, the historical highest air pressure, and the historical lowest air pressure. The unit is hectopascal. If it is less than one hectopascal, it will be rounded off. The historical air pressure will be recorded from the time the watch is bound. Swipe left on the air pressure page to view the altitude value. The altitude range is -200~9000 meters, and the air pressure range is 700-1100 hPa.
Note:
1. Since the altitude will be affected by the surrounding environment, the altitude data is for reference only;
2. If there is a large deviation, please tap [Check for updates] icon at the bottom of device page in the [Mi Fitness] APP, update the watch to the latest firmware version and try again.