Your iPhone makes sure you never miss AMBER and other kinds of emergency government alerts.
In the United States, AMBER — America's Missing: Broadcasting Emergency Response — and other kinds of emergency government alerts are relayed to your iPhone using the same Notification Center system as your other iPhone alerts, like iMessage and Calendar.
Depending on the nature of the alert, which can include child abductions and impending natural disasters, it's a great feature that can prevent injury and save lives. Many lives. So, by their nature, these alerts don't respect Do Not Disturb settings. They NEED to get through.
That can be shocking, however, especially if they happen when you're sleeping, driving, or otherwise not expecting a loud noise to come from your iPhone. That's why, ultimately, AMBER and other alerts work at your discretion.
How to control AMBER and Government Alerts on your iPhone
Launch the Settings app on your iPhone.
Tap on Notification Center and scroll all the way to the bottom.
Under the Government Alerts section, toggle the AMBER Alerts or Government Alerts option on or off to enable or disable them.
Turning off AMBER and other alerts can cost lives, including yours. If a natural disaster is coming your way, and you don't know about it, you have no way to save your life or the life of your family.
That why they're loud and shocking. They're meant to get your attention, instantly — and big, loud, and noisy is the way to do that.
So, while you can disable them, you shouldn't. Not unless you have some other way to be reliably alerted about emergencies.