Highest temperature in Seoul on July 11?

Platform comparison

Market context

The market tracks the peak Celsius temperature at Incheon International Airport on 11 July 2026, a date that historically sits within Seoul’s early-July heat window. Current crowd-implied probability for any specific outcome is effectively zero, yet Polymarket data shows 31°C as the frontrunner at 37%, with 30°C next at 30%, suggesting the 0% figure reflects a liquidity or display anomaly rather than a true consensus against heat [1].

Historical maxima for early July in Seoul typically cluster between 25–30°C, but extreme outliers exist: in 2023, Seoul hit 37.7°C, the highest early-July reading in 117 years of records [2][5]. South Korea’s all-time record reached 41.0°C at Hongcheon, though Incheon’s coastal location usually moderates peaks compared to inland stations [3]. Programmatic traders should model a distribution skewed right, weighting the 31–33°C bands more heavily than the crowd’s current flat probability suggests.

Key catalysts include the Korea Meteorological Administration’s daily 09:00 KST forecast updates and real-time Wunderground feeds for RKSI, the designated resolution source [1]. Traders should monitor the Climate Shift Index alerts for East Asia, which recently flagged record-breaking summer heat in South Korea and Japan as a systemic risk for July 2025–2026 [6]. A conditional order strategy could auto-execute on Wunderground spikes above 30°C before the 12:00Z settlement cutoff, exploiting the lag between live data and market repricing.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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 Fees. 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 Kalshi Fees trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.