Highest temperature in Seoul on May 23?

Platform comparison

Active sub-markets

Market context

On 23 May 2026, Seoul's highest temperature will be recorded at Incheon International Airport Station and settled against historical weather data from Wunderground. The 0% crowd probability suggests either extreme confidence in a specific temperature band or minimal trading activity on this particular date range. Seoul's late-May climate typically sits between 22–28°C, with occasional spikes above 30°C during early heat waves, making the range selection critical for accurate settlement.

Historical May temperatures at Incheon show considerable year-to-year variance. The past decade records highs ranging from 19°C in cooler years to 33°C during anomalous warm periods, with a median around 26–27°C. This volatility explains why traders on Kalshi and Betfair may price different ranges distinctly—decimal odds on Betfair allow finer granularity than Polymarket's binary YES/NO structure, potentially creating arbitrage opportunities if one platform's book undervalues mid-range outcomes. KYC requirements differ across venues; Polymarket's international accessibility versus Kalshi's US-focused regulation shapes which trader bases engage with this contract.

Monitoring the Korean Meteorological Administration's seasonal forecasts through May 2026 will signal whether atmospheric patterns favour above or below-median temperatures. Any announced heat-wave watches or cold-front systems in April–May reporting should shift probability distributions noticeably. Traders comparing platforms should note settlement timing: Wunderground's historical data often finalises within 24–48 hours, but discrepancies between airport station readings and city-centre measurements occasionally arise, affecting edge calculations across books with different data-source dependencies.

Methodology

This page compares Highest temperature in Seoul on May 23? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. Live odds come from the Polymarket order book; the other venues' contract details are maintained manually because their APIs aren't directly comparable. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

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 reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.