Though you're kind of right, some years have a hotter August on average than other years and I believe this one was hotter for much of America. As in noticeably

Though you're kind of right, some years have a hotter August on average than other years and I believe this one was hotter for much of America. As in noticeably hotter for many days. I assume the government charts are aware of this, so that 1F degree higher is measured by averaging ~5 Augusts together thirty years ago and comparing them to the most recent few Augusts.