iOS 13 alarm volume

Hey there bder1921,

Thanks for reaching out to Apple Support Communities. I understand your iPhone’s alarms are louder than expected when it’s locked. I’ll be happy to help with this.

It sounds like once you unlock your iPhone, the volume slider in Settings > Sounds & Haptics > Ringers And Alerts is set to where you want it correct? If so, try restarting your iPhone and see if this has any impact on the issue:

Restart your iPhone, iPad, or iPod touch

If not, create a new alarm on your iPhone for 5 minutes out and lock the device. See if this alarm is louder than expected. If not, you may need to remove your current alarms and set new ones.

If that doesn’t work, back up your iPhone and restore it to factory settings and test an alarm in this state:

How to back up your iPhone, iPad, and iPod touch

Restore your iPhone, iPad, or iPod to factory settings

If an alarm works as expected in the factory condition, restore the backup to your iPhone, and test again:

Restore your iPhone, iPad, or iPod touch from a backup

Cheers 

The reality is the alarm will play at the volume set on your phone when the alarm goes off. The reason the volume reduces when you look at your phone is called Attention Aware and it's doing exactly what it's designed to do.