Trade: Highest temperature in Seoul on May 11?

Market context

On 11 May 2026, the highest temperature recorded at Incheon International Airport Station will determine which range this market settles into. The resolution uses historical weather data from Weather Underground, capturing the daily maximum across all daylight and evening hours at Seoul's primary weather observation point. Currently, the order book reflects a 0% implied probability, suggesting traders are pricing in either extreme confidence in a specific outcome or minimal liquidity across the available temperature bands.

Seoul's May climate typically produces highs between 24–28°C, with occasional spikes toward 30°C during early heat waves. Historical May records at Incheon show temperatures have exceeded 30°C in roughly one-third of years since 1990, whilst readings above 32°C remain uncommon but not unprecedented. The current flat probability distribution on Polymarket's order book may reflect genuine uncertainty about which specific range will capture the day's maximum, or it could indicate thin trading activity that hasn't yet established consensus pricing around the most likely outcomes.

Traders should monitor South Korean meteorological forecasts from late April onwards, as seasonal weather patterns and any early-season high-pressure systems moving across East Asia will become clearer. The Korea Meteorological Administration typically issues extended outlooks 10–14 days ahead; any signals of an anomalous warm spell or cooler-than-average conditions in early May would shift expectations materially. Urban heat effects specific to Seoul proper may also diverge slightly from the airport station reading, though Incheon's coastal location moderates extremes compared to central Seoul.

Resolution source

This market settles from the official outcome published at https://www.wunderground.com/history/daily/kr/incheon/RKSI. A proposer submits the final result to the UMA optimistic oracle on Polygon; the two-hour dispute window closes and payouts clear in USDC.

How to trade this market step by step

The mechanics for trading "Highest temperature in Seoul on May 11?" are the same as any other PolyGram event contract. Each YES share resolves to $1 if the event happens, or $0 if it doesn't. The current price between 0¢ and 100¢ is the market's probability estimate, set live by the order book.

1. Sign in on polygram.ink with your email — no full KYC under $1,500 lifetime trading volume.
2. Deposit USDC on Polygon (lowest fees, ~$0.01 per transaction) or Ethereum. Funds credit after 12 confirmations.
3. Pick a side. Buy YES if you believe the event will happen; buy NO if you think it won't. The current YES price reflects the market's collective probability.
4. Size your position. If you stake 100 USDC at 50% YES, you'll receive shares that pay $200 if YES resolves true — a 100% gross return. If NO resolves, your shares are worth $0.
5. Set risk controls (optional). Stop-loss, take-profit, and limit-order types all supported. Use the trade ticket's slippage box to cap your maximum entry price.
6. Wait for resolution. When the event resolves on-chain via the UMA optimistic oracle, the winning side settles to 100¢ automatically and USDC hits your balance within seconds. Withdrawable to any wallet you control.

How active is this market?

$140K in lifetime turnover and $7K of resting liquidity puts this market in the top 30% by volume for weather contracts on PolyGram. Order-book depth is thin — large orders may need to be split across the book or executed as limit orders.

Last 24 hours alone saw $120K in turnover, well above the lifetime daily-average for this market — a clear sign of news catalysing trader activity right now.

The market has been open for under a month — fresh enough that information asymmetry remains a real factor.

Higher-volume markets tend to have tighter spreads and faster price discovery — meaning the displayed YES/NO percentages are more likely to reflect the true crowd-implied probability rather than a single trader's directional view.

Key terms

YES / NO share

A binary outcome token that pays $1.00 if the underlying claim resolves true (YES) or false (NO), and $0 otherwise. The market price between 0¢ and 100¢ is the implied probability.

CLOB

Central limit order book. The matching engine that pairs YES buyers with NO buyers (effectively the same trade). Polymarket's CLOB on Polygon executes trades on-chain via the conditional-tokens framework.

Liquidity

USDC capital sitting in resting limit orders inside the order book. Deeper liquidity means smaller slippage on large trades and a tighter bid-ask spread.

UMA optimistic oracle

The on-chain dispute system that settles each Polymarket market. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution.

Slippage

The difference between the displayed mid-price and your fill price. Affects market orders most; limit orders avoid slippage but may take time to fill.

Conditional token

ERC-1155 outcome share issued by Gnosis Conditional Tokens on Polygon. The token type that resolves to $1.00 or $0.00 at settlement.

See the full prediction-market glossary →

Frequently asked questions

Risk and regulatory note

Prediction-market positions can lose 100% of staked capital. Outcomes are uncertain by definition — historical accuracy of crowd-implied probabilities is high in aggregate but not for any single market. PolyGram does not provide investment advice. Trade only with capital you can afford to lose.

Regulatory status varies by jurisdiction. Germany, the United States, and most EU countries treat Polymarket-style event contracts under one of three frameworks: financial derivative, gambling product, or unregulated novel asset. Consult local counsel before trading.

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