Highest temperature in Seoul on July 12?

Platform comparison

Market context

Seoul is bracing for peak summer heat as traders assess the likelihood of record-breaking temperatures on 12 July 2026 at Incheon International Airport. The market currently assigns a 0% probability to any outcome, suggesting the crowd expects conditions to remain well below the thresholds that would trigger a resolution, despite recent regional extremes.

Historical data frames this near-zero probability as a reaction to volatility rather than a lack of heat potential. In early July 2025, Seoul hit 37.7°C, the highest for that period in 117 years, while South Korea later recorded an all-time national peak of 41.0°C in Hongcheon [1][2]. However, July 2025 was the second-hottest July on record nationally, with averages of 27.1°C, indicating that while extreme spikes occur, sustained record-breaking days are less common [5]. The 0% implied probability likely reflects a divergence from sportsbook lines that may still price in tail-risk heatwaves, whereas prediction markets have priced out the event entirely.

Traders should monitor the Korea Meteorological Administration’s daily heatwave advisories and real-time Wunderground feeds for Incheon, as these dictate settlement [3]. A recent Anadolu Ajansı report highlighted Seoul’s 37.7°C peak in 2025 as a benchmark for early July extremes, making it a critical reference for future volatility [8]. With the settlement window closing at 12:00 UTC on 12 July, any sudden shift in forecast models or official advisories could rapidly alter the odds, though current forecasts suggest highs between 28°C and 37°C for the month [6].

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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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 PolyGram. 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.

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?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

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.