Highest temperature in Seoul on July 31?

Platform comparison

Market context

The key event is the **highest recorded temperature at Incheon Intl Airport Station on 31 July 2026**, with settlement tied to the day’s peak reading rather than Seoul city proper. That distinction matters: the market is referenced to the airport station in Incheon, where coastal moderation usually trims extremes versus inland Seoul, yet the current crowd-implied **0% YES** looks aggressive given the ongoing regional heat pattern and the fact that contracts like this can still settle into the upper-20s or low-30s Celsius if the day stays merely warm rather than exceptional.[4][15]

Historical comparables point to why the line may be underestimating tail risk. Seoul and the wider capital region have recently produced repeated heat records, including 37.8°C at Seoul’s official station in late July 2026 and 38.3°C on 31 July 2018, while July averages in Seoul are usually far lower, around 29°C daytime highs.[11][2][15] By contrast, Incheon’s forecast high for today was only 31°C in one morning briefing, which helps explain why some traders may price the contract as effectively dead; but airport observations can still surprise upward if cloud cover clears and the boundary layer mixes hot inland air towards the coast.[4]

The main catalysts to watch are the afternoon temperature trend, any KMA updates on heat advisories, and whether sea breezes keep Incheon below the higher Seoul readings seen elsewhere in the capital area.[4][5] Forecasts cited today still showed Seoul around 33°C and much of South Korea in a heatwave, with regional daily highs reaching the mid-30s elsewhere, so the relevant question is not whether the country is hot, but whether Incheon Airport itself can briefly spike into the market’s winning range before the 12:00 UTC settlement cut-off.[4][5]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Seoul on July 31? 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 Best Prediction Markets 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

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 Best Prediction Markets UK 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.