South Korea · Climate data from the Korea Meteorological Administration
Seoul dresses for a 14°C–30°C / 57°F–86°F window across the months we cover. Seoul moves block to block in style codes the way Tokyo does — Hannam-dong is quiet luxury and minimalist tailoring, Seongsu is industrial-creative streetwear, Gangnam reads polished K-fashion magazine, Hongdae is loud youth culture. Summer is two distinct seasons inside one calendar: late-June through mid-July is *Jangma* (장마), the Korean monsoon rainy season with 13+ rain days and 414mm of rainfall, and August is humid 30°C / 86°F+ heat with sudden afternoon downpours. AC inside cafés and subways runs aggressive (16-18°C / 61-64°F; a thin layer in the bag is a Seoul daily essential. Korean style favors precision — clean color blocking, structured tailoring, sneakers selected with care — over casual ease.
Across the 4 months we cover: morning lows from 14°C / 57°F (May) to afternoon highs of 30°C / 86°F (August).
What to wear in Seoul in May 2026: KMA data (24°C / 75°F, 14°C / 57°F mornings), the K-fashion Hannam-Seongsu uniform, pre-Jangma dry warmth, and AC-contrast layer rules.
What to wear in Seoul in June 2026: KMA data (28°C / 82°F, 8 rain days, late-June Jangma onset), pre-monsoon humid warmth, and the K-fashion early-summer uniform.
What to wear in Seoul in July 2026: KMA data (29°C / 84°F, 13 rain days, peak Jangma monsoon), the wettest month strategy, K-fashion rain-ready uniform, and AC layer rules.
What to wear in Seoul in August 2026: KMA data (30°C / 86°F, 12 rain days, post-Jangma humid heat), late-summer afternoon storms, and the K-fashion humid-summer kit.
The neighborhood you sleep in affects what reads as appropriate more than the calendar does. Seoul's style scene anchors on the districts below — each leaf page calls out the local register (smart-casual, undone, technical, party) so the capsule maps to the streets you'll actually walk on.
Every leaf page on this hub is built from four data layers: climate normals from the Korea Meteorological Administration; named-authority etiquette and style references (Vogue, Condé Nast Traveler, Business of Fashion, the relevant local press); resident write-ups and traveler-forum reports for the failure modes tourists get wrong; and the editorial avatar pool that visualises each capsule on a person rather than a moodboard. Every DO names a reason. Every DON'T names a failure mode. We retest before each seasonal refresh — the editorial-modified date at the bottom of each leaf is the receipt.
Climate numbers come from the Korea Meteorological Administration — the national meteorological service for South Korea. Daily highs and lows, rain days, and daylight hours are 1991-2020 normals (the international standard, refreshed every decade). Capsule pieces and what-to-avoid notes are stress-tested against Seoul resident write-ups, named-stylist sources where the city has a documented uniform (Vogue Paris under Emmanuelle Alt for Paris, Vogue Japan and i-D Tokyo coverage for Tokyo, NYMag's The Cut for New York), and the failure modes locals actually flag in city forums and traveler reports.
Because the morning-low to afternoon-high swing inside one Seoul month already changes the silhouette — and the swing between months is much bigger than that. May mornings start at 14°C / 57°F; August afternoons hit 30°C / 86°F. A single packing list that tries to span both ends up wrong at both. Each month here is a different capsule, calibrated to the climate band that actually shows up on the ground.
4 so far: May, June, July, August. We ship climate-and-event-distinct months only — adjacent months that share more than 60% of the same capsule pieces don't get separate pages, because near-identical leaves erode the credibility of every other page on the site. The full coverage plan is in our internal CLAUDE.md (the editorial brief governs every page that ships).
the Korea Meteorological Administration 1991-2020 normals are the version cited on every leaf — the international meteorological standard, updated by every national service every decade. We restate the numbers as raw averages on the leaf pages ("30°C / 86°F afternoons") rather than the year range, so the figures don't read as stale. The next normals refresh covers 2001-2030 and lands in 2031 — we'll bump every page when it does.
Editorial rule, enforced in CI: every DO line names a specific reason ("merino sinks under a trench so a damp morning doesn't show through your knit"); every DON'T names a specific failure mode ("suede stains the first time light drizzle catches it"). We ban "timeless," "elevate your style," "must-have," and "effortless" — they're the giveaway phrases of generic AI fashion writing. If a sentence could open any city's guide, it gets cut. Seoul's guide reads like Seoul, not like a packing-list aggregator.