The US Bureau of Labor Statistics (BLS) provides monthly estimates of the Consumer Price Index (CPI), a measure of inflation, for the United States. The BLS typically releases its CPI estimates for a month in the first half of the following month.
There are two versions of CPI. One is typically known as headline CPI which is the full measure, while the other is typically known as core CPI, which doesn't include food and energy.
Below is a graph of the annual change in CPI in the US, not seasonally adjusted, from the Federal Reserve Bank of St. Louis. The annual change is measured from December of the year in question to the December of the prior year. Note that the underlying source is the BLS, though the chart may update with subsequent estimates published by the BLS and may not reflect the initially published estimates.