Analyze the quote “Gregor’s eyes then turned to the window, and the overcast weather...”

Gregor's eyes then turned to the window, and the overcast weather--he could hear raindrops hitting against the metal window ledge--completely depressed him.

This line begins the third paragraph of Chapter One. In the first paragraph, Gregor wakes up realizing he has been “turned into a monstrous vermin,” and the rest describes his new appearance. In the second paragraph, as he wonders what has happened, he looks around his room and finds it is unchanged. In paragraph three, he looks out through the window.
The cloudy sky and rain have the effect of depressing him, and he decides to go back to sleep. His new shape has made him uncomfortable, however, as he is stuck on his back. Contemplating his new form, he tries in vain to move. After pondering his situation, beginning to move a bit, and talking through the locked door with his mother, Gregor returns to considering the weather. He reminds himself that jumping to conclusions will not help his predicament, but he should aim for “thinking things over calmly--indeed, as calmly as possible…” As he has done in the past when he made that kind of effort,

he fixed his eyes as sharply as possible on the window, but unfortunately there was little confidence and cheer to be gotten from the view of the morning fog, which shrouded even the other side of the narrow street. "Seven o'clock already," he said to himself as the alarm clock struck again, "seven o'clock already and still such a fog."

Hoping that he might turn back into himself, Gregor’s contemplation of the fog goes along with his recognition that his transformation is likely permanent. The fog outside is a metaphor for the confusion in his head.

And for a little while he lay quietly, breathing shallowly, as if expecting, perhaps, from the complete silence the return of things to the way they really and naturally were.