Highest temperature in Seoul on July 31?

Platform comparison

Market context

Polymarket is pricing this contract at **0% YES** today, which on-chain means almost no USDC is currently being put to work on the view that the day’s top reading at Incheon Intl Airport Station will land in the contract’s winning temperature range. The market settles through Polygon conditional tokens, so the only thing that matters is the official Wunderground daily high for that station before the 12:00 UTC settlement cut-off, not Seoul city temperatures in general.

That 0% print sits against a backdrop of unusually severe Korean heat. Reuters reported that South Korea set a new national temperature record of 41.4°C in Yangsan on 31 July 2026, while Yonhap noted Seoul’s July 2018 high of 38.3°C and the city’s broader history of only a handful of readings above 38°C since 1907.[1][2] For a trader, the useful comparison is that Incheon is coastal and typically cooler than inland heat centres, but the present national pattern shows enough thermal intensity to keep upper-tail outcomes alive if the marine influence weakens during the afternoon.

The main catalysts are the Korea Meteorological Administration’s day-ahead and intraday forecasts, cloud cover, sea breeze timing, and whether the current heatwave peaks before or after the noon UTC settlement window. Local reporting on 31 July said Seoul and Incheon were already in the high-20s Celsius early in the morning, with daytime highs in the region expected in the low-to-mid 30s, which would be consistent with a modest but not extreme upside move.[4] Traders watching the book should track whether updated forecasts shift the expected maximum towards the upper 30s, because that is what would force Polymarket repricing from a near-zero conditional token stance.[4][8]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to PolyGram, which mirrors the Polymarket order book directly.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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.

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 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.