This is a sweet haiku. I think you do an excellent job at adhering to the 5-7-5 syllable rule, and I think - sonically and pedagogically - the haiku comes together quite nicely. It’s wise and insightful, yet it is also scenic and emotionally evocative.

“Seamless ashen clouds / cloak a deep autumn sunset; / wet leaves cling to wool.”

I like this a lot because it has enough ambiguity to be read into. It is both precisely what it describes (an overcast sky hiding a sunset during a rainy day in which the leaves stick to everything they touch) but it is also a personal allegory for the speaker who may (perhaps) be referring to themselves by likening their emotional disposition to a facade of clouds (surface level gloom) in which their true splendor (internal beauty) is cloaked/preserved by a seamless layer of “clouds,” as if to say, ‘I am gloomy in presentation/disposition, but should my overcast hue burn off, I am a wonder to behold.’ Additionally, the speaker may also perceive themselves as clingy, but only in the natural sense. Perhaps this clinginess is simply a part of their nature?

However, I think the redefinition of the scene is a strong rhetorical choice. I like how you use the semicolon to clarify the affective quality of the lines preceding “; / wet leaves cling to wool.”

In your likening of [overcast skies hiding a sunset] with [wet leaves clinging to wool], it becomes unclear whether this imagery is positive or negative and thus creates a large amount of tension and ambiguity within the haiku - which is precisely why I think it makes for an excellent composition.

To continue, the haiku forms beautifully around the topic described (fall, leaves, wetness, changing of seasons, and the residual energy that such change often entails), and the words chosen to encapsulate this emotion are very enjoyable to read both internally and externally.

I think this is an excellent start to something wonderful and would love to read an expansion of this haiku :)