What does the chart below each data product in the Explore Data Products page represent?

This chart shows whether data are available for any given spatial location for any given month. Gray represents that data are unavailable, and blue represents that at least some data are available. A blue box does not indicate that data are complete for that location/month combination. The default view, Summary, rolls up the availability of data across all sites. If data are available for at least one site for a given month, then the box at that month will appear blue. If the box is gray, there is no data available for that month at any site. If you click on the Site button, the graph will expand to show availability for each site denoted by its four-letter abbreviation. Clicking on State or Domain will roll up availability similarly to the Summary view. For example, if State is chosen and there is a blue box available for a given month, then data are available at least one site in that state for the month of interest.