Dream pop is the first-listed genre for Taylor Swift’s “august.”
The song is also described through guitar pop and soft rock, but dream pop appears first in the song’s infobox. Its atmosphere supports that classification: the recording uses prominent reverb, layered textures, shimmering guitar sounds, strings, and keyboards rather than a sharply minimal pop arrangement.
Folklore is often broadly categorized as an indie folk or alternative album, yet “august” has a more pop-oriented production than some of its quieter neighbors. Aaron Dessner described it as close to a pop song within the album’s overall sound.
Genre labels can vary between critics, databases, and listeners. This answer refers specifically to the first genre listed for the song in its English Wikipedia article, not to every style associated with the track.