Highest temperature in Seoul (Incheon) on August 1?

Platform comparison

Market context

Incheon Airport’s **highest temperature on 1 August** is priced as a **0% YES** event, so the market is treating a reading in the target band as virtually impossible. The crowd consensus is firmly on the under, but that leaves obvious room for a contrarian heat-risk trade if the day breaks sharply hotter than the pre-open forecast.

The historical frame is straightforward: early August is normally one of the hottest parts of the Korean summer, with Seoul and Incheon typically posting August highs around the high 20s to low 30s Celsius, while travel guides and monthly forecasts put Incheon’s August daytime maximum near **29°C** and Seoul’s around **29°C to 30°C**.[2][5][20] That said, current conditions are not average; Reuters reported South Korea’s hottest-ever national reading on 31 July at **41.4°C** in Yangsan, after several consecutive days above 40°C in parts of the country, which shows the broader heatwave has been exceptional rather than routine.[6] Local reporting on 1 August also pointed to morning temperatures of **27.0°C in Incheon** and daytime highs of **31–36°C** or even **32–39°C** nationally, which supports the idea that the favourite is the lower-temperature outcome, but the market’s 0% YES pricing looks vulnerable if the airport station outperforms the city forecast.[4][1][17]

For traders, the key catalyst is the Korea Meteorological Administration’s short-range forecast and any intra-day heatwave updates, because the settlement uses the single highest reading at Incheon Intl Airport Station before the window closes.[3][13] The immediate watchpoint is whether the airport benefits from full sun and sea-breeze suppression, or whether marine influence caps the peak below the hotter inland readings seen elsewhere in the country; that dependence makes the under the favourite, but also leaves a value spot on the over if forecasts for nearby Seoul and Incheon keep ratcheting up through the session.[4][10][17]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Who Will Win 2026 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.