Apple Watch altimeter

I live at 112m and my altimeter was showing ~340m.

to fix it I opened my Apple Watch app on my iPhone and then clicked on “All watches” and pressed the little “i” next to my watch. Then I clicked the “unpair” button.

I then opened my iPhone “Settings”, then clicked on my name to open the “Apple ID” menu. I then removed my Apple Watch from the device list.

I then followed apple’s instructions for pairing the watch to the iPhone.

During the pairing process I chose the option to restore from iCloud backup. After the watch completed the restore process my altimeter took a few minutes before it showed the altitude.

My altimeter now says ~106m, which is good enough for me :) off by just 5%. There’s low pressure outside which might cause the difference.. I’ll try again on a sunny day :)

The only help references I can find regarding the altimeter are in this part of the User Guide, Use Compass on Apple Watch (Apple Watch SE and Apple Watch Series 5 and later only) - Apple Support I do not see in there anything regarding any ability to calibrate it.

What type of wristband do you use? If the protective cover was the issue (or the wristband) I think the readings would be way off all the time.. Try my steps again, but set it up as a new watch. No iCloud restore and make sure the Apple Watch is removed from the iCloud device list.

My readings are still quite perfect. Are your readings off when indoors AND outdoors, or are they worse indoors? The altimeter will probably be affected by powerful ventilation systems. When I worked out on a treadmill in a gym that was located in a tall building my previous Garmin smart watch thought I was walking 120 floors up during my 60 minute workout....

So if your readings are off inside buildings with ventilation system I think it’s regarded as normal and nothing you can do about it.. The building sort of manipulates the air pressure, which is a pain in the a**.. :(

If your readings outdoors are still way off it might be an issue with the sensor. Contact apple support on their chat and they will ask you to go through several steps to debug it.

If you still have problems they will probably ask you if you want to get it serviced. I did it yesterday actually, with my AirPods Pro. UPS will come to my door to pick up my AirPods and all I have to do is wait for a week or so. That might be a solution for you if your altimeter is still problematic.

So I found this happens when a low pressure weather system comes in. There needs to be a manual clibration added. I'm at ~35m, but when we get a rain storm for example, it says I'm at 335m with no way to manually calibrate.

Galaxy Watch does this, why can't Apple Watch? I have the SE btw.

New test today... I’m at 135,5m and the watch shows ~134m. Good enough for me :) the unpair/pair process in my previous post seems to be a permanent fix. At least for me

Sounds like a problem with the barometric altimeter settings,and they need to be reset by unpairing and re-pairing the watch.