For the last few weeks I’ve been jarred awake by an overly loud alarm; it didn’t seem to always be so loud, but maybe I’d forgotten?
Nope. Not the case at all. When I updated to iOS 13.4 it set my ringer and alarm volumes to 100%. Now that I’ve reduced the volume I’m hopeful that my wake ups will be a lot more peaceful than they’ve been for the last few weeks.
To change the volume of the built-in Apple alarm: Go to Settings > Sounds & Haptics. Under Ringers And Alerts, drag the slider left or right to set the volume. As you drag, an alert will play, so you can hear how the volume changes. Turn on Change with Buttons to use the volume buttons on your device to change the alarm volume.