Highest temperature in Seoul (Incheon) on August 8?

Platform comparison

Market context

Polymarket is pricing this Seoul temperature contract at **0% YES** in USDC on Polygon, which means the market is effectively saying the specified Incheon Airport reading on 8 August is not expected to land in the winning temperature band. The settlement logic matters here: the market resolves off Weather Underground’s **Daily Observations** table for Incheon Intl Airport Station, not the broader Day High & Low summary, so traders need to watch the station-level trace rather than the headline forecast figure.[4][12]

The backdrop is a very warm August climate, but the distribution is what matters for a binary range market. Seoul’s August average high is around 30°C, and historical 8 August highs have often sat in the low- to mid-30s, with a record 36.0°C for that date in one compiled history source.[1][2] Recent forecast snapshots for 8 August 2026 point to highs in the mid-30s Celsius for Seoul generally, while broader historical data show that late-summer extremes can push well above average when hot, humid air dominates.[1][11] That helps explain why even a 0% print can still conceal meaningful tail risk if the observed station temperature spikes after the market opens.

A trader should focus on the timing and source dependence: the contract settles by the highest reading logged in the Daily Observations table up to the settlement window close, so the key catalysts are the intraday temperature path, any afternoon surge, and whether local storms or marine influence cool the airport station relative to city forecasts.[4][13] KMA mid-range forecasts can frame the setup, but the actual settlement source is Weather Underground, so the final outcome depends on what the station records, not what a general Seoul forecast implies.[16][4]

Sources: 1 · 2 · 3 · 4 · 5

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 Kalshi 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

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

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%.