When viewing the Azure Storage usage report, the data stored values differ depending on the selected time interval. Since Azure Storage is a provisioned resource, its usage or data stored should remain relatively consistent across time intervals.
Although the amount of storage remain relatively consistent throughout the month, the usage and cost details received from Azure are reported on a daily basis via the API. Azure Storage Usage are determined by the storage capacity and the access tier (e.g., Hot, Cool, Archive). Each day, Azure calculates and reports a computed usage amount based on these parameters.
When the platform aggregates this daily data (usage × cost) across all days of the month, the total matches the monthly cost charged in the Azure bill.