Participating laboratories report weekly to CDC the total number of coronavirus tests performed that week and the number of those tests that were positive. Because reporting delays may be expected for some laboratories, the data shown for the most recent weeks may be less complete than others. Each point in the trend charts below shows the average number of coronavirus tests performed by census tract and the average percentage of those who were positive from three adjacent weeks: the specified week and the weeks before and after. This is also known as the 3-week centered moving average.
In the United States, annual community outbreaks of coronavirus infections typically occur in late fall and winter. There may be variation in the timing of cases between regions and between communities within the same region.
About Census Regions and Divisions [1 MB, 2 pages]
United States Northeast Census Area
Table: Northeast United States percent of positive coronavirus tests, by week
Midwestern United States census tract
Table: Midwestern United States percent of positive coronavirus tests, by week
Census tract of the southern United States
Table: Southern United States rate of positive coronavirus tests, by week
Western United States census tract
Table: Western United States' rate of positive coronavirus tests, by week
