Highest temperature in Seoul (Incheon) on August 5?

Platform comparison

Market context

Incheon Airport’s hottest reading on 5 August is the number that settles this market, and the crowd’s **0% YES** implies it is pricing the outcome as effectively unreachable. The favourite case is a benign, cloudy or rainy day that caps the airport below the relevant band, while the underdog is a sharp late-morning or early-afternoon spike that pushes the day’s maximum into the target range; for a summer Korean station, that second path is not exotic in itself, but the market is treating it as remote.

The historical frame does not support a zero-price view. August is one of Seoul’s hottest months, with average highs around **28–31°C** and official/forecast sources repeatedly pointing to mid-30s potential on the warmest days, including a Seoul daytime high of **38°C** in the latest local heat-wave coverage[1][2][12][15][19]. That does not guarantee the airport station prints the same extreme, but it does show that the consensus climate regime is firmly in the heat-stress camp rather than an unusually cool regime. The value angle is therefore not an easy call on a scorching print; it is more about whether the market has over-discounted ordinary August heat, with the contrarian case being a clear-run hot window before any showers arrive.

Catalysts are straightforward but time-sensitive: the short-range KMA outlook, airport-adjacent cloud/rain timing, and whether today’s heat warning persists into the midday heating peak[1][4]. Seoul-area forecasts in the market set include highs from the upper-20s to high-30s, with some services flagging patchy rain and others showing much hotter conditions, so the key dependency is whether the station sits under the hotter western-core air mass or a rain-influenced pocket[1][3][5][11]. If showers develop earlier than expected, the underdog loses momentum quickly; if skies stay open through early afternoon, the consensus zero looks vulnerable to a repricing.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Seoul (Incheon) on August 5? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Who Will Win 2026. 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 Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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.