Highest temperature in Seoul on July 3?

Platform comparison

Market context

Seoul is currently experiencing its most prolonged nighttime heatwave for July, with temperatures never dipping below 29.3°C between Wednesday night and Thursday morning, setting a new record for tropical nights since modern observations began over a century ago[1]. This extreme baseline frames the current 0% crowd-implied probability for a specific high-temperature range, as historical data shows July highs in Seoul rarely exceed 91°F (32.8°C) and typically hover around 85°F (29.4°C)[3]. While South Korea recorded its second-hottest July in 2025 with an average of 27.1°C, the recent spike to 37.7°C in early July represents an 117-year anomaly rather than a standard seasonal trend[5][8].

A power-user evaluating this market programmatically must monitor the Korea Meteorological Administration’s hourly forecasts and Wunderground’s real-time station data for Incheon International Airport, the designated resolution source[1]. The primary catalyst is the persistence of the current tropical night record, which has already reached 22 nights this month, breaking the 1994 record of 21[1]. Traders should also watch for any official announcements regarding heatwave emergency protocols or updates on the all-time national heat record of 41.0°C set in Hongcheon, which could influence regional temperature expectations[4]. The settlement window ending 2026-07-03T12:00:00Z requires precise data ingestion from the specified URL to confirm the daily maximum[1].

The market’s utility lies in its ability to test conditional order strategies against volatile weather data, where the 0% probability suggests the crowd expects the temperature to fall outside the defined range entirely[1]. Given that Seoul’s average July high is 29.4°C and the recent record of 37.7°C is an outlier, a programmatic approach would likely short the specific range if the forecast indicates a return to mean conditions rather than continued extremes[2][3]. The dependency on Wunderground’s specific Incheon station data means any discrepancy between Seoul city readings and the airport station could invalidate the trade, making real-time data verification essential for accurate execution[1].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Seoul on July 3? 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 Polymarket Review UK. 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'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 Polymarket Review UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.