Pronóstico: Highest temperature in Seoul on July 18?

Platform comparison

Market context

Seoul's summer heat peaks in mid-July, with the city regularly recording daily highs between 28–32°C during this period. The settlement mechanism tracks the maximum temperature recorded at Incheon International Airport's weather station on 18 July 2026, resolving to whichever temperature bracket contains that single highest reading. Polymarket currently prices this contract at 0% YES across all temperature ranges, reflecting either incomplete market formation or traders awaiting historical baseline data before committing capital on USDC across Polygon's conditional token infrastructure.

Historical records show Seoul's July temperatures cluster predictably: the past decade's mid-July highs have ranged from 26°C in cooler years to 34°C during heat waves, with 30–31°C representing the modal outcome. The 2018 heat wave pushed temperatures to 39°C in central Seoul, though Incheon Airport—situated on the coast—typically records 2–3°C lower readings due to maritime influence. This geographical buffer makes extreme outliers less probable at the measurement station than in the city centre, anchoring expectations toward the 28–33°C band for most scenarios.

Traders should monitor South Korea's meteorological forecasts from late June onwards, particularly the Korea Meteorological Administration's seasonal outlooks and any El Niño or La Niña patterns affecting the Western Pacific. Typhoon activity in early-to-mid July could suppress temperatures, whilst high-pressure systems stalling over the peninsula would elevate them. The settlement window closes at 12:00 UTC on 18 July 2026, requiring traders to resolve positions before Wunderground's historical data becomes final for that calendar day.

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

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'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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Qué Es trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.