Highest temperature in Seoul (Incheon) on August 12?

Platform comparison

Market context

Seoul's maximum temperature on 12 August 2026 will be recorded at Incheon International Airport Station and measured against historical August heat patterns. The settlement mechanism specifies the Daily Observations table on Weather Underground as the authoritative source, distinguishing it from summary high-low figures that occasionally diverge. Current crowd-implied probability sits at 0% across prediction markets, suggesting either extreme confidence in a specific temperature band or sparse liquidity in this particular contract.

August in Seoul typically peaks between 28–32°C, with extreme heat events pushing toward 35°C occurring roughly once per decade. The 2018 heat wave saw Incheon record 38.4°C on 1 August, whilst the 2022 summer remained more moderate. Historical volatility in August temperatures—driven by monsoon activity, high-pressure systems, and occasional typhoon proximity—means single-day forecasts carry material uncertainty even with modern meteorological models. The 0% probability reading suggests traders may be concentrated in adjacent temperature bands rather than absent entirely.

Traders monitoring this contract should track Korea Meteorological Administration forecasts released in late July and early August, which typically refine 10–14 day outlooks into actionable precision. Typhoon trajectories in the Western Pacific during early August will materially influence whether Seoul experiences typical summer heat or cooler, wetter conditions. Cross-platform comparison between Polymarket and Kalshi shows no meaningful divergence in pricing, indicating consensus pricing rather than arbitrage opportunity. The settlement window closes at 12:00 UTC on 12 August, allowing only morning-of adjustments based on real-time observations.

Methodology

We track Highest temperature in Seoul (Incheon) on August 12? 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

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

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 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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.