Thermal Expansion and Contraction in Two Story Townhome
That's not right at all. Nothing should be constantly repeating or over that many hours. Usual sounds are just nails sliding in &amp; out of their pockets, 1-pop or crack going in with the cold &amp; 1-pop or crack coming out with the heat, for just a few nails or sounds total. Or, plastic &amp; aluminum siding rustling momentarily in direct Sun. Maybe, it's just the screening on the vents that might be loose &amp; flapping in the breeze.

Get a Carpenter out to check on whether something's actually broken &amp; to sink a bunch of screws &amp; get rid of the usual suspects. Screws don't need to join pieces, they can just span a gap &amp; keep things from moving. Wall &amp; ceiling cracks, if any, are a great indicator of movement areas. Or, it could be something electrical that contracts at night, the Carpenter might notice this, but get an Electrician too.