You might occasionally read on the AWS Service Health Dashboard a message referring to issues on “a single Availability Zone in the US-WEST-1 Region” or “We are investigating degraded performance for a small number of EBS volumes in a single Availability Zone in the AP-SOUTHEAST-1 Region”
You might wonder why AWS does not disclose the name of the AZ affected to simplify the live for their customers. They cannot as there is not a unique name. Even if the AZ is persistent for the live of your account, the name of the AZ is account dependent. Different accounts map the same AZ (for example us-east-1c) to different physical locations and availability zones in the AWS region. As for AWS documentation:
An Availability Zone is represented by a region code followed by a letter identifier; for example, us-east-1a. To ensure that resources are distributed across the Availability Zones for a region, we independently map Availability Zones to identifiers for each account. For example, your Availability Zone us-east-1a might not be the same location as us-east-1a for another account. There’s no way for you to coordinate Availability Zones between accounts.