HUTs and PUTs tend to follow similar patterns year after year, with some variations for Olympics months. During the year, there is some variation by month but not dramatic differences.
It has often been theorized that Americans watch much less television during the summer. In actuality, TVB’s analysis of June, July and August NTI averages find that the fall-off is consistent and not severe nationally. Some local markets, particularly in the South, may actually have increased HUTs because of the hot summers.
Click for the NTI primetime HUT tables by month (XLS)