Highest temperature in Busan on August 18?

Platform comparison

Market context

On 18 August 2026, the highest temperature recorded at Gimhae International Airport Station in Busan will determine the settlement of this market. The contract divides outcomes into discrete temperature ranges in Celsius, with resolution tied specifically to the Daily Observations table on Weather Underground rather than summary figures. The current crowd-implied probability of 0% YES suggests either extreme confidence in a particular outcome or sparse liquidity across the range options.

Busan's August climate presents a narrow historical band for forecasting. Daily highs in mid-August typically cluster between 28–32°C, with occasional peaks above 33°C during heat waves. The 2018 Korean heat wave pushed Busan temperatures to 34°C in early August; more recently, August 2023 saw sustained highs in the 31–33°C range. These precedents establish that extreme outliers (sub-25°C or above 36°C) carry minimal historical frequency, though tropical systems can introduce volatility. The 0% probability across the board suggests traders may be awaiting clearer seasonal patterns or initial range definitions before committing capital.

Traders monitoring this contract should track the Korean Meteorological Administration's seasonal forecasts and any tropical cyclone activity in the Western Pacific during early-to-mid August 2026. Typhoon season intensity and track predictions typically solidify 7–10 days before potential impact, creating a catalyst window for probability shifts. Cross-platform comparison reveals minimal activity on Kalshi or major sportsbooks for this specific weather event, concentrating liquidity risk on Polymarket. The reliance on Gimhae Airport's official station data—rather than city-centre observations—eliminates urban heat island variance, anchoring outcomes to a consistent measurement point.

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.

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