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 market currently prices all temperature ranges at 0% on Polymarket, suggesting either insufficient liquidity or traders awaiting clearer atmospheric signals before committing USDC collateral to conditional tokens on the Polygon network.

Mid-July in Seoul typically brings high summer heat, with historical records showing daily maxima between 28–33°C during this period. The city experienced a peak of 39.6°C in July 2018 and regularly sees temperatures exceeding 32°C in the third week of summer. Incheon Airport, located on the coast, tends to record slightly cooler readings than central Seoul due to maritime influence, though the differential rarely exceeds 2–3°C. These historical patterns provide the baseline against which the 18 July outcome should be evaluated; traders should reference Korea Meteorological Administration archives for comparable years to calibrate expectations around the upper and lower bounds of the resolution ranges.

Catalysts shaping the forecast include the East Asian summer monsoon's intensity in early July, tropical cyclone activity in the Western Pacific, and the strength of the Tibetan high-pressure system. The Korea Meteorological Administration typically issues extended forecasts by mid-June; traders should monitor their seasonal outlooks and any heat-wave warnings issued in the week preceding settlement. Recent patterns suggest that La Niña conditions, if present, could suppress extreme heat, whilst any blocking high-pressure systems would elevate peak temperatures substantially above the 30°C threshold.

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

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

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.