A pertinent question would be whether Delta has more or less effectively swept through most of the UK?
The US has a lot of heavily populated areas that have not yet seen a big Delta wave. Those areas / states / cities are also those where, for better or worse, stronger mitigation has been in place. I would postulate those areas may see continued moderate increases in cases until the end of October. After that, well, we shall see.
The UK and Israeli Delta waves have continued to spread to previously uninfected pockets, and maintained a moderate transmission rate.
It seems likely to do that here as well, until most everyone has been exposed. When seasonal conditions are favorable, many modelers anticipate another National upturn (wave) of some degree.