Ipchu & Cheoseo: Autumn Approaches입추·처서 — 더위가 물러간다

Ipchu, around August 7, is the solar term that declares the 'start of autumn' — usually while Korea is still baking in peak heat, which makes it the calendar's most ironic entry. Cheoseo, around August 23, means the heat 'stops' or subsides, and this one has traditionally delivered: mornings and evenings turn noticeably cooler, humidity drops, and the season genuinely pivots. A beloved proverb captures it — 'by Cheoseo, even the mosquitoes' mouths go crooked,' meaning the nights get too cool for them to bite. These terms were farming signals: around Ipchu, farmers plant the napa cabbage and radish that will become winter kimchi at kimjang in November — autumn is when you prepare for winter, and the calendar says so out loud. Modern Korea still watches these dates. News programs report whether Cheoseo brought its promised cool, and in recent years the answer is often 'not yet': heat waves and tropical nights increasingly stretch past Cheoseo, and Seoul researchers have found mosquito activity now peaking in autumn rather than midsummer — the old proverb bending under climate change. Still, when the first genuinely cool evening arrives in late August, Koreans feel it collectively: the Han River parks fill with picnickers, and everyone says the same thing — Cheoseo has done its work.