Highest temperature in Seoul on May 22?

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Market context

The temperature at Incheon International Airport on 22 May is resolved from the day’s recorded maximum before the settlement window closes, so the key question is whether late-morning sunshine can lift the airport above the low-20s Celsius. Seasonal context points to a mild late-spring profile rather than a heat setup: Seoul’s May averages sit around the low 20s Celsius, but Incheon is coastally influenced and often runs a touch cooler than inland Seoul, with sea-breeze effects limiting sharp afternoon spikes. That helps explain why a 0% yes price is not the same as a certainty of sub-threshold weather; it simply means the market has not assigned any measurable chance to the specific bracket being discussed.

On comparable late-May days, the highest temperature usually depends on whether cloud clears early enough for strong insolation, and whether a maritime flow keeps the western side of the capital region subdued. WeatherSpark’s Seoul climatology shows daily highs rising through May but still rarely exceeding the mid-20s Celsius, while AccuWeather’s late-May ranges imply plenty of room for highs in the 20s but less evidence of extreme heat. On Polymarket, the crowd view is shown as implied probability; on Kalshi or Smarkets you would instead compare contract prices or decimal-style quotes after fees, and on Betfair the same event would usually reflect a spread of back/lay prices and commission. KYC and access also differ: Kalshi is US-regulated, Smarkets is UK-facing, and Polymarket is typically broader offshore access.

For traders, the main catalysts are the final short-range forecasts and any change in cloud cover, wind direction or shower timing from the Korea Meteorological Administration and the Wunderground station feed used for settlement. A stronger-than-expected morning clearance would favour a higher max, while lingering cloud, onshore flow or rain would cap the reading. The market closes at 12:00 UTC, so any midday warm-up after that point will not matter unless it has already been captured in the recorded maximum.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Seoul on May 22? 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

Where can I trade this market with the lowest fees?

On PolyGram, 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.

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.

Do I need to KYC for this market?

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