In this paper, I read Claude McKay’s partaking in the English sonnet tradition in Harlem Shadows as being a fundamental part of—and not, as many commentators have suggested, counter to—the poet’s and book’s radical politics. Upon contextualizing my readings alongside critics including Houston A. Baker, Jr., Kamau Brathwaite, and Winston James, I perform close readings of McKay’s poems “Subway Wind” and “Outcast.” I specifically analyze how these poems imagine climatic ‘currents’ through images and metaphors of racially marked colonial spaces, which the poems, I suggest, also poetically perform through the actualization of the sonnet form as discursive currents redirected toward liberatory politics.