Highest temperature in Seoul (Incheon) on August 21?

Platform comparison

Market context

Seoul's summer temperatures in late August typically range between 26–32°C, with occasional peaks above 33°C during heat waves. The Incheon International Airport meteorological station, which serves as the official observation point for this market, records hourly readings that feed into Weather Underground's Daily Observations table—the specified resolution source. August 21st falls within Seoul's warmest period, when Pacific high-pressure systems and tropical moisture converge, though the exact daily maximum depends on cloud cover, wind patterns, and whether any tropical systems approach the Korean peninsula.

Historical August data from Incheon shows that temperatures exceeding 35°C occur roughly once every three to five years during this month, whilst readings above 37°C remain rare. The 0% crowd probability suggests traders are pricing in either a conservative baseline or uncertainty about accessing reliable forecast data two years ahead. For programmatic approaches, the key is establishing a data pipeline that monitors Weather Underground's Daily Observations table directly rather than relying on summary forecasts, since the market explicitly prioritises hourly station data over aggregated high-low figures.

Traders should track the Korea Meteorological Administration's seasonal outlooks and monitor tropical cyclone activity in the Western Pacific during late August 2026, as these represent the primary catalysts for anomalous heat. Conditional orders tied to tropical storm warnings or heat-wave advisories issued by KMA would allow automated position adjustments. The two-year settlement window means early-stage traders face significant data uncertainty, making this market more suitable for those building systematic weather models than for reactive traders.

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Polymarket Review UK, which mirrors the Polymarket order book directly.

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

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.

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%.