A parent drives home with a newborn after a storm. The speaker mentions the baby is "swaddled in your carseat," so the poem seems to catch one of the first journeys of the child's life. The morning's forecast looked threatening, with clouds "swirling malignant" on the radar, but the sky has cleared by the time they set out, and most people are still indoors.
The mood begins in quiet caution and slowly opens into awe. The plowed snow muffles sound, the highway is unusually clear, and the whitened trees stand against "impossibly radiant" pink evening light. The speaker leaves the radio off and listens instead, hearing "some strange music" in the trees and the road. In the last lines, that music seems to come from "everything that had sung you into being." The speaker's feeling is tender and wondering: the ordinary world looks charged with meaning because a new life is sitting in the back seat. The title, "Dawn Chorus," fits this sense of a fresh beginning, even though the scene happens in the evening.