iOS 27 alarms only flash—no sound or vibration

I can confirm this worked for me. I faced the exact same issue and i unpaired my old apple watch as it wouldn’t go upto watchOS 27, and lo and behold the alarm now rings and vibrates.

This is 100% and update issue, unlike how someone mentioned that its device specific, and can’t be attributed to the update.

Test the alarm sound by opening the Clock app and playing the sound manually: This will help you confirm if the issue is with the alarm sound itself or the trigger mechanism.

Specific days of the week assigned to an alarm are crucial for it go off. At the same time Alarm Tone setting is also equally important. See the pics below

1. Make sure that the volume is turned up and not on silent or vibrate mode. You can check this by using the volume buttons on the side of your iPhone or by going to Settings > Sounds & Haptics and adjusting the volume slider.
2. Verify that you have selected a sound for your alarms. You can do this by going to the Clock app, selecting the Alarm tab, and tapping "Edit" in the top left corner of the screen. Then, tap on the alarm you want to check and make sure you have chosen a sound.
   1. Probably you have set the Alarm Sound to NONE. Watch the GIF below
   2. 
3. Sometimes, a simple restart can resolve temporary software glitches. Turn off your iPhone, wait for a few seconds, and then turn it back on.
   1. Restart the device. That's it.
   2. Still not solved --> Force restart iPhone - Apple Support
4. If the issue persists, you can try resetting all settings on your iPhone. This will not erase your data but will reset all personalized settings to their default values. Go to Settings > General > Transfer & Reset > Reset > Reset All Settings and confirm the action. Note that you will need to reconfigure your settings afterward. All settings—including network settings, the keyboard dictionary, the Home screen layout, location settings, privacy settings, and Apple Pay cards—are removed or reset to their defaults. No data or media are deleted.
   1. Reset All Settings: Return iPhone settings to their defaults - Apple Support:- Return iPhone settings to their defaults
   2. You can return settings to their defaults without erasing your content.
   3. If you want to save your settings, back up your iPhone before returning them to their defaults. For example, if you’re trying to solve a problem but returning settings to their defaults doesn’t help, you might want to restore your previous settings from a backup.
5. Make sure you have the latest updates installed.
   1. Update Over-the-Air (OTA) —> Update your iPhone or iPad - Apple Support (IN)
   2. Update using iTunes/Finder —> Update your iPhone, iPad, or iPod touch - Apple Support (IN)

Heisenberg914 wrote:

Immediately after updating to iOS 27,

Not every issue an individual encounters on their device can be attributed to an iOS update. If the update itself were the root cause, then every device running that same version of iOS would exhibit the identical problem. In such a scenario, the forums would be flooded with countless posts reporting the same malfunction, creating an unmistakable wave of complaints that no one could possibly overlook. The absence of such widespread reports strongly indicates that the issue is not systemic, but rather specific to the device in question.

I've got the same issue when updated to IOS27.0. Mine is an older iphone SE so judging from all the reports I see here, I would say it is DEFINITELY an IOS update problem. Since there are reports on multiple types of Iphones, this needs to be fixed by Apple ASAP.

I had this issue today as well - first time one of my alarm triggered since the latest iOS update, and the alarm made no sound despite all settings set to make sound & no issues with sound prior to the update.

I don’t have an Apple Watch, so that can’t be the root cause of the issue.

My alarms didn’t go off at all this morning, even though they were set correctly. So since ive update my phone to ios 27 the alarms are delayed or wont even go off at all, i dont have a Apple Watch so i do believe it is a bug that needs looking into

I had this happen with iOS 27.0 and on my Apple Watch Ultra 2 as well. A couple of times, slept right through important meetings as a result.

my iPhone just updated to 27.2 and it just happened this morning again.

doesn’t seem to be resolved after the update!!

Alarms on my iPhone are ringing quite fine with iOS 27.