Highest temperature in Seoul (Incheon) on August 10?

Platform comparison

Market context

Seoul’s highest temperature on 10 August is being priced against a very hot late-summer backdrop, but the contract’s settlement is tied to the *Incheon Intl Airport Station* reading in Weather Underground’s Daily Observations table, not the headline day-high figure. Polymarket currently implies 34°C as the likeliest outcome at 44%, with 33°C close behind at 40%, while the market’s displayed crowd probability is still 0% YES, so there is a clear gap between the live outcome pricing and any simple yes/no interpretation of the contract.[2]

That spread is easier to read when set against recent comparables. Reuters reported Seoul forecast near 39°C on 6 August as South Korea’s heatwave intensified, and local coverage said Seoul had already topped 40°C in parts of the city earlier in the month, with KMA expecting hot conditions to persist into next week.[8][7] At the same time, seasonal guidance from AccuWeather points to 93–94°F on 10 August, roughly 34–34.5°C, which sits neatly in the market’s leading bands rather than at the extreme upper end.[1][16] That combination suggests traders are leaning on forecast guidance more than on the most dramatic recent readings.[2][8]

The key catalyst is the day’s actual observation sequence: if the Incheon station posts a peak early enough, it can lock the contract before later revisions, because Polymarket says temperature alterations are only considered until the first datapoint for the following date appears.[2] Traders should watch the KMA short-range forecast, any late-morning shift in cloud cover or wind, and whether the local heat eases enough to keep the station’s high in the low-to-mid 30s rather than the upper 30s. The market is still small enough that fresh forecast updates can move it quickly, so the main divergence to watch is between the forecast-led 33–34°C cluster and any late-session push towards 35°C or higher.[2][4]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Seoul (Incheon) on August 10? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Best Prediction Markets UK, which mirrors the Polymarket order book at 0% fees.

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.

UK Frequently Asked Questions

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 Best Prediction Markets 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 are the best prediction markets for UK traders in 2026?

For UKGC-regulated markets: Betfair Exchange (sports, politics) and Smarkets (sports, politics, lower commission than Betfair). For broader global event prediction: Polymarket (deepest liquidity, 0% fee, USDC settlement). For US-regulated option: Kalshi (USD, limited UK payment options). Most serious UK traders use a combination of Betfair for regulated sports and Polymarket for broader markets.