Why am I still being charged for CloudWatch?

There are a few reasons why you might still be seeing charges for CloudWatch even after deleting log groups and metrics:

1. Retention of data: CloudWatch metrics are stored for 15 months, even if they're not visible in the console. You can't manually delete these metrics; they expire based on retention schedules.

2. Custom metrics: While AWS-provided basic monitoring metrics are free, you may be charged for custom metrics you've created or for additional opt-in metrics from other services.

3. S3 monitoring: If you enabled monitoring for S3 file access, this could be causing additional charges.

4. Other services: Some AWS services may have CloudWatch features enabled that you're not aware of, such as EC2 detailed monitoring or Lambda Insights.

To reduce or eliminate CloudWatch charges:

1. Review your AWS bill to identify specific CloudWatch costs.
2. Check for any custom metrics or filters you may have created.
3. Review other AWS services for enabled CloudWatch features and disable them if not needed.
4. For S3, check your buckets for any extra metrics or filters and remove them.

Keep in mind that you can't completely disable CloudWatch as it's an integral part of AWS services. However, by carefully reviewing and adjusting your settings, you can minimize or potentially eliminate additional charges beyond the free tier.
Sources
Delete a metric in CloudWatch metrics | AWS re:Post
Disabling Cloudwatch | AWS re:Post

Hi, apologies for the confusion, but the above message has some incorrect details:

1. Metrics are only charged when ingested. CloudWatch does NOT charge for metrics retention. CloudWatch charges for log retention, so if you deleted your log groups you’re good.
2. The points 2, 3 and 4 above overlap, and are the most likely cause for your ongoing charges: EC2 detailed monitoring, Lambda Insights and S3 file access are 3 very commonly used ways to opt-in to additional metrics, which can induce spend in CloudWatch. If you don’t remember which services you opted in to additional metrics, the best starting point to identify the service is to use the Cost Explorer and filter on charges generated by CloudWatch, then break those charges down by usage type and operation. The usage type for metrics will indicate in the operation field which service is sending opt-in metrics. See https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/cloudwatch_billing.html#cloudwatch_billing_costs for additional guidance on how to leverage the Cost Explorer view.