You are coming from the bleak dust, and I am waiting for you in late autumn! what's the meaning

This sentence means that you have come from a dusty and desolate environment, and I will wait for you when autumn is thick and the weather is getting cold.

This sentence expresses an emotion of waiting and expectation, and implies the speaker's missing and expectation for someone. At the same time, it also expresses the speaker's feelings about autumn, and thinks that autumn is a season full of thoughts and expectations.