Highest temperature in Seoul on July 17?

Platform comparison

Market context

On 17 July 2026, the real-world event determining this market’s outcome is the highest temperature recorded at Incheon International Airport in Seoul, measured in degrees Celsius. In prediction markets, a YES share pays out if the selected temperature range contains the actual peak temperature, while a NO share pays out if it does not. This specific market resolves based on data from Wunderground for the Incheon station, with settlement finalising at 12:00 UTC on that day.

Historical patterns suggest the current 0% crowd-implied probability for a YES outcome on the frontrunner range is likely mispriced, as July in Seoul routinely sees peaks near 31°C. Recent data shows Seoul recorded its highest temperature since 1908 during a heatwave expected to persist until mid-July, with the city also experiencing its longest nighttime heatwave for July, where temperatures stayed above 25°C overnight [2][3]. The market’s frontrunner is actually 31°C at 76% probability, indicating traders expect a hot day rather than the extreme cold implied by a 0% YES chance for the current selection [1].

Traders should monitor daily weather bulletins from the Korea Meteorological Administration and real-time Wunderground updates for the Incheon station, as these are the primary catalysts for price movement. No specific policy announcements or scheduled events will alter the temperature, but sudden shifts in monsoon activity or heatwave intensity could rapidly change the implied odds. The resolution source is fixed, so any discrepancy between forecast models and live station data will drive immediate trading activity.

Sources: 1 · 2 · 3

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 Prediction Market UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.