In a preëlectric world, moonlight served as both lamp and guide, illuminating our paths. Bashō wrote:
月ぞしるべこなたへ入らせ旅の宿
tsuki zo shirube konata e irase tabi no yado[1]
the moon’s is your guide:
please come this way
a traveler’s inn
—Bashō[2]

This was one of the first haiku Bashō ever published, written when he was only 21. At this time, the popular style for renga, of which haiku—called hokku at the time—was the first verse, was to make clever allusions to poems and songs from the past. Bashō was very good at this. He discarded it later in life as he attempted to find the true essence of haiku, but when he was young he was quite the master at doing it.
The reference here is to a Noh play called “Tengu on Mount Kurama” (鞍馬天狗, kurama tengu) where cherry blossoms instead of the moon are a guide. This kind of fun allusion is why the popular style of renga at the time was called haikai no renga—“comic renga”—often shortened to simply haikai.
To go off on a tangent, the tengu in that Noh play is Sōjōbō (僧正坊) the king of the tengu.[3] It was said he had the strength of 1000 normal tengu. Sōjōbō is best known for (supposedly) teaching Minamoto no Yoshitsune the art of swordsmanship and strategy, tips that Yoshitsune would use well when he led the Minamoto forces to win over the Taira in their war for control of Japan way back in 1180–1185. But that is a story for another time.
Anyway, moon (tsuki) is an autumn season word, making this an autumn poem.