Highest temperature in Seoul (Incheon) on August 19?

Platform comparison

Market context

Seoul's weather on 19 August 2026 will be measured by the highest temperature recorded at Incheon International Airport Station, with settlement determined by the Daily Observations table on Weather Underground rather than summary figures. The market currently prices this at 0% YES across all temperature bands, reflecting either extreme uncertainty about which range will resolve or technical pricing dynamics on Polygon where USDC-denominated conditional tokens trade. Traders holding YES positions would profit if the recorded high falls within their selected range; the market's current structure suggests no single temperature bracket commands meaningful conviction among active participants.

August in Seoul typically experiences peak summer heat, with historical highs consistently exceeding 30°C. Data from the past decade shows Incheon Airport recordings regularly reaching 32–35°C during mid-August, with occasional extremes above 36°C during heat waves. The 2018 heat wave pushed temperatures to 39.6°C in Seoul proper, though airport stations often register slightly lower readings due to location and measurement protocols. These precedents establish the baseline against which traders should calibrate their range selections.

Catalysts affecting the 2026 forecast include seasonal monsoon patterns—the East Asian summer monsoon typically peaks in July-August, potentially moderating temperatures through cloud cover and precipitation. Long-range climate models from the Korea Meteorological Administration, typically released in June-July, will provide the first institutional guidance on whether 2026 August conditions favour above or below-average heat. Tropical cyclone activity in the Western Pacific during late summer could also suppress temperatures if systems approach the Korean Peninsula.

Methodology

We track Highest temperature in Seoul (Incheon) on August 19? 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

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 Polymarket Alternative 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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.