Yea it visually looks like the aggregate in the concrete is retaining moisture, even after the driveway has dried all day in the hot sun.This quote is hidden because you are ignoring this member. Show Quote
But its been fairly dry the last month. And the spots were not there in May or June when it was way more wet. Our driveway is steep-ish so there isn't any standing water on or around it.
Although I guess it's been fairly humid the last couple weeks, maybe thats causing it too.