Highest temperature in Seoul on July 18?

Platform comparison

Market context

Seoul's peak temperature on 18 July 2026 will be measured at Incheon International Airport Station and resolved against historical weather data from Wunderground. The settlement window closes at midday UTC, meaning traders must account for the full calendar day's high before the market locks. This creates a practical constraint: real-time monitoring of the station's hourly readings becomes necessary in the final hours, as the highest temperature often occurs in early afternoon local time (roughly 13:00–15:00 KST).

July in Seoul typically sees highs between 28–32°C, with occasional peaks above 33°C during heat waves. The 0% crowd probability suggests either extreme confidence in a specific temperature range already selected elsewhere, or insufficient liquidity drawing traders into this particular bracket. Historical precedent matters here: Seoul recorded 39.6°C in August 2018 during an exceptional heat event, but mid-July averages closer to 29–30°C. Traders building algorithmic monitoring should cross-reference the Korea Meteorological Administration's forecasts alongside Wunderground's historical patterns, as the two sources occasionally diverge on station-level precision.

The key catalyst is the East Asian summer monsoon system's positioning in early-to-mid July 2026. If a high-pressure ridge dominates the Korean peninsula, temperatures will trend toward the upper 30s; if monsoon moisture penetrates northward, cloud cover and precipitation will suppress peaks into the mid-20s. Conditional order logic should trigger on KMA's 10-day outlook releases, typically issued five days prior to the settlement date. Wunderground's data feed updates hourly, making it suitable for bot-based position adjustments during the final 24 hours.

Methodology

We track Highest temperature in Seoul on July 18? 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

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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?

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.