Highest temperature in Seoul on May 28?

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Active sub-markets

Market context

On 28 May 2026, the highest temperature recorded at Incheon International Airport Station will fall into one of several defined ranges. The settlement will draw from Wunderground's historical weather database, which aggregates hourly readings throughout the day and reports the peak value in Celsius. This market differs materially from comparable weather contracts on Kalshi or Betfair in its geographic specificity: it locks to a single airport weather station rather than a broader metropolitan average, reducing noise from urban heat-island effects but increasing sensitivity to localised conditions.

Seoul's late May climate typically produces highs between 24–28°C, though the range can extend to 30°C during warm spells. Historical data from the past five years shows May 28 temperatures clustering around 25–27°C, with only one instance exceeding 29°C. The current 0% implied probability across all temperature brackets suggests either a technical settlement issue or genuine uncertainty about market liquidity. Polymarket's decimal-odds format and lower KYC requirements may explain why this market exists here rather than on Smarkets or Betfair, where weather contracts typically command tighter spreads and higher participation.

Traders should monitor South Korean meteorological forecasts released in the week preceding settlement, particularly any warnings of early-season heat waves or unusual pressure systems. The Korea Meteorological Administration publishes extended outlooks five to ten days ahead. Seasonal patterns favour temperatures in the mid-to-upper 20s Celsius; any deviation would require documented atmospheric anomalies. Fee structures on Polymarket (2% maker/taker) versus Kalshi's tiered model will affect edge calculations on tight probability bands.

Methodology

We read Highest temperature in Seoul on May 28? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live quote comes directly from the Polygon order book; the other three are listed with their platform attributes — fees, KYC, settlement currency, payment options — because a 1:1 contract comparison without API access would be guesswork.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). Polymarket Alternative UK routes every trade directly into Polymarket's on-chain settlement, which is why payouts land fastest.

FAQ

Where can I trade this market with the lowest fees?

On Polymarket Alternative UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket Alternative UK 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.

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.

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.