That's probably an extreme example, but I believe some progs had it modeled. Here's the 00z 3k NAM from the night before.
Low 70s dews in SNE during the morning and then mixing out into the 60s and pockets of <= 60F in E MA from BYV to BOS where the hottest temps were achieved. We often get that early to mid morning dewpoint bump as the dew evaporates off into the low levels and then come afternoon the deeper mixing allows the drier air back down to the surface. In the evening the surface cools and reaches saturation rapidly so you get the dew formation (countryside) before 2m fully drops to the overnight mins. (I know you know this...just throwing it out to the non-mets)
Here's the number of days per year at CON with 70F+ dewpoints at each hour. There's a clear late morning bump, mid afternoon "min", and then the late evening spike around sunset. Then it continues to radiate, reach saturation, and the T/Td make that slow drop together until sunrise.
Obviously places like BOS or ORH don't radiate well so they tend to stay mixed 24hrs.