Autumn is also fall for a reason. It is the season during which most deciduous foliage will fall. Some deciduous trees that lack good fall color may look neater without their shabby old foliage. Sadly though, the splendidly colorful deciduous trees must shed also. All that collective debris that succumbs to weather and gravity gets messy, and can clog gutters.
Evergreen plants shed too. They are just sneakier about it. Some shed old foliage during spring or summer while simultaneously replacing it to stay evergreen. Some shed slowly but steadily for several months, rather than concentrating the mess within a brief season. Many shed during autumn though, as wind and rain dislodge their lingering older foliage.
Whether deciduous or evergreen, various plants shed at various rates. Monterey cypress shed so steadily through the year that they are never caught in the act. Fruitless mulberry can defoliate in just a few days if frosted suddenly enough. Sudden defoliation seems to be messier, but can be an advantage. For example, gutters may need cleaning just once.
Weather is also variable. Rain began a bit early this year. The associated dampness can accelerate defoliation for some species. Other species respond more to temperature. An early chill may accelerate their shedding. It is therefore impossible to predict when it will be necessary to rake fallen leaves or clean gutters. There are simply too many variables.
Unfortunately, the weather that causes leaves to fall is the very same weather that makes raking and cleaning gutters so unpleasant. No one wants to work in the garden while it is cold. Nor does anyone want to get onto a dangerously wet roof to clean gutters. There is no need to rake or clean gutters before rain and cool weather cause debris to fall though.
It should be obvious when it is necessary to rake leaves from lawn, pavement and street gutters. Bigger leaves tend to be more problematic by clogging drainage. Smaller leaves may just as easily stain pavement or decking though. Roof gutters are not so visible, but probably need cleaning while raking is necessary nearby, and hopefully before clogging.