Highest temperature in Seoul on May 22?

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Market context

Seoul’s late-May climate is already warming, but the day’s top reading is still usually driven by a narrow afternoon window rather than a dramatic heat event. Climate normals for May in Seoul show highs rising from about 20°C at the start of the month to around 25°C by month-end, with average daily highs near 21°C and lows near 11°C. Historical extremes in the city during May can reach the upper 20s Celsius, but those are outliers rather than the baseline, which makes any specific “highest temperature” market sensitive to whether a warm air mass settles in before midday and how quickly cloud cover builds.

For comparable cases, the key reference point is that late-May warmth in the Seoul area often lands in the low-to-mid 20s Celsius, with occasional spikes into the upper 20s when skies are clear and winds are light. WeatherSpark’s May profile for Seoul shows highs commonly between 20°C and 25°C, while AccuWeather’s monthly outlook for Seoul points to a much wider band for the month overall, with highs broadly from the low 20s into the high 20s Celsius. That combination suggests the market’s 0% YES price is not a claim of cold weather, but a sign that traders are being careful about the exact station and the fact that one brief warm reading may be enough to settle the relevant band.

The main catalysts are the morning and early-afternoon observations at Incheon Intl Airport Station, plus any shift in cloud cover, sea-breeze flow, or precipitation around the Seoul-Incheon corridor. If skies clear quickly and winds stay light, the daily maximum can arrive early and sit a few degrees above the day’s average; if marine air, showers, or thicker cloud arrive, the top reading can be held closer to the low 20s Celsius. Traders should watch the Korea Meteorological Administration short-range forecasts and any updates from Wunderground’s daily history page for Incheon, since the market settles on the final recorded high for that station once the day is complete.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Seoul on May 22? on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Is this market available outside the US?

PolyGram is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does it cost to trade on PolyGram?

Zero. PolyGram routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.