Highest temperature in Seoul on May 28?

Platform comparison

Active sub-markets

Market context

Seoul's highest temperature on 28 May 2026 will be measured at Incheon International Airport Station and resolved via Weather Underground's historical records. The settlement window closes at midday UTC on that date, meaning traders must account for the full day's temperature range before the market locks. The 0% crowd probability suggests either extreme confidence in a specific outcome or minimal liquidity; across Polymarket, Kalshi, and Betfair, such compressed odds typically reflect either very few positions or a consensus so strong that no one is willing to take the opposing side.

Seoul's late May temperatures historically cluster between 22–28°C, with occasional peaks above 30°C during early heat waves. The city experiences high humidity and variable spring weather patterns through the final week of May, making extreme outliers (both above 32°C and below 18°C) plausible but uncommon. Comparable May 28th data from prior years shows the airport station recording highs between 24–27°C in most instances, though 2018 saw 29.2°C. This historical range frames how tightly the resolution brackets are likely to cluster.

Traders should monitor long-range weather forecasts from late April onwards, as they improve significantly in the two weeks before settlement. The Korea Meteorological Administration publishes extended outlooks that typically become reliable five to ten days prior. Kalshi's strict KYC requirements and US-focused weather markets mean this Seoul-specific contract may see deeper liquidity on Betfair or Smarkets, where international weather betting is more established. Fee structures vary—Kalshi charges 2% on winnings, whilst Betfair's commission scales with volume—making position sizing calculations dependent on your chosen platform.

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

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?

Kalshi 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.

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 Kalshi Alternative UK?

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

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Kalshi Alternative UK triggers a quick verification flow that finishes in minutes.