What inference can be made about the night based on the language Sexton uses in "The Starry Night"?

In Sexton's poem, "the night boils with eleven stars." This metaphor suggests that the night is hot but also adds perhaps a touch of surrealism to the description of the night. Firstly, in order for something to boil it must be a liquid. Secondly, when something boils it bubbles and produces steam. Thus, from this metaphor, we have a surreal image of a liquid night bubbling and steaming.
In the second stanza, the line, "Even the moon bulges in its orange irons," gives an impression of the night as restless. The moon seems to want to escape from its orbit, or from its metaphorical "irons." Together with the aforementioned image of the night boiling, this metaphor suggests that the night is straining to break loose or spill over.
In the third stanza, Sexton writes of the "rushing beast of the night." This is an example of zoomorphism, whereby an inanimate object is described as an animal. The word "beast" also implies a dangerous, ferocious animal. Thus, the night is here described as alive and menacing, very much in-fitting with the connotations of "restlessness," noted above.
Overall, one can infer from the language of the poem that the night is, from the speaker's perspective, alive, restless, hot, and menacing.