Highest temperature in Seoul (Incheon) on August 4?

Platform comparison

Market context

Seoul’s heat has intensified into a proper late-summer spike, with local media reporting the first serious heatwave warning of the season and daytime highs around 38°C, even as some scattered showers are expected later in the day. For Incheon, the latest comparable forecasts still point to a very hot afternoon rather than a cool-off, with August 4 marked by forecast highs around 37°C and only limited rain coverage.[2][3]

That matters because the market settles on the day’s *highest* temperature at Incheon Intl Airport Station, not the average or the late-evening reading. August in Seoul is normally the hottest stretch of the year, and climatology for early August already sits near the annual peak, with typical highs in the mid-30s Celsius and the hottest-day window clustering around this date.[1][14][16]

For traders, the key catalysts are the timing of the heat peak, any cloud build-up or showers in the afternoon, and whether the sea-breeze influence at Incheon trims the top end versus inland Seoul. The market also sits in a period when heat warnings are active across the capital area, which supports an elevated ceiling unless rainfall arrives early enough to cap the afternoon maximum.[2][5]

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 Prediction Today, which mirrors the Polymarket order book at 0% fees.

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

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 Prediction Today. 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?

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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.