Highest temperature in Seoul (Incheon) on August 4?

Platform comparison

Market context

Polymarket is pricing this Seoul/Incheon airport heat contract at **0% YES** for now, so the market is effectively saying the Incheon Intl Airport Station’s recorded high on 4 August 2026 will land outside the winning temperature band. Because settlement uses the single-day maximum from Wunderground rather than citywide averages, traders are looking at one exact airport observation on Polygon, with value encoded in USDC-backed conditional tokens rather than a generic Seoul forecast.

That 0% print has to be read against the local climatology and recent forecast tone. August in Seoul is normally hot, with average highs around 84°F/29°C and typical daily highs in the high 20s to low 30s Celsius, while comparable August guides put the month among the hottest and most humid of the year.[1][14][16][18] For 4 August specifically, current outlooks point to very warm conditions, with Seoul forecasts near 38°C and Incheon near 37°C, alongside heat-wave warnings and only scattered showers that are not expected to meaningfully cool the area.[2][3][5] That combination makes a high-temperature result plausible enough to watch closely, even if the present market price implies the crowd sees it as outside the resolved range.

The main catalysts are the next KMA updates, any shift in the heat warning, and whether afternoon showers arrive earlier or more widely than forecast, since cloud cover and rain can cap the day’s peak before the airport station prints its maximum.[3][4][10] Traders should also track the timing of the settlement window: once the day turns, the contract resolves off the highest temperature recorded for the full day at Incheon Intl Airport Station on Wunderground, so late-day heat still matters more than the morning reading.[2][4]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Seoul (Incheon) on August 4? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Kalshi UK, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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 Kalshi UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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 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.