Highest temperature in Seoul on July 20?

Platform comparison

Market context

Seoul faces its peak summer heat on 20 July 2026, with the Incheon International Airport station expected to record the day’s highest temperature in degrees Celsius. Historical data confirms July is South Korea’s wettest and most humid month, where daily highs routinely approach 30°C and humidity levels exceed 80%, often pushing the perceived temperature above 34°C at midday [1]. The rainy season, known as Jangma, typically spans late June to mid-July but can extend into late July, introducing variability that traders must weigh against the consistent thermal baseline of the season [1].

On Polymarket, this contract currently trades at 0% probability for the YES outcome, reflecting the crowd’s confidence that the temperature will fall outside the specific range defined in the market description. The market settles via the UMA Optimistic Oracle using USDC on the Polygon network, with payouts triggered automatically once Wunderground publishes the official daily maximum for the Incheon station [2]. Traders should monitor real-time weather updates from Wunderground’s history page for RKSI, as the resolution depends entirely on the highest recorded temperature for all times on 20 July, with no room for estimation or proxy data [2]. Any sudden shift in cloud cover or precipitation intensity during the afternoon could alter the final reading, making live monitoring essential before the settlement window closes at 12:00 UTC on 20 July 2026.

Sources: 1 · 2

Methodology

We track Highest temperature in Seoul on July 20? 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

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 Kalshi UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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 Kalshi 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.