Highest temperature in Seoul (Incheon) on August 6?

Platform comparison

Market context

Seoul’s temperature on 6 August is the event that matters here, but settlement uses the **highest reading at Incheon International Airport Station** on that day, not the city centre forecast. That distinction matters because the airport site sits on the coast and can diverge from inland Seoul by a few degrees, especially when sea breezes or local showers blunt the peak. Current market pricing at 0% YES implies the crowd is treating a qualifying high as very unlikely, even though regional forecasts were calling for severe heat, with Incheon around 38°C and Seoul around 39°C under an official heatwave warning.[2][3][10]

Historically, early-August temperatures in Seoul are already near the seasonal peak, with August average highs around 84°F and the highest daily average high on 6 August, but actual extremes depend on short-lived synoptic patterns.[1][15] Comparable heat events show that 39°C-plus is possible in the capital area, yet the airport station’s coastal location makes an exact threshold harder to pin down than a city forecast would suggest.[3][11] In market terms, a 0% implied probability usually reflects either thin liquidity or a belief that the required range is above the plausible realised maximum, rather than certainty about the weather itself.

The main catalysts to watch are the final KMA short-range updates, the timing of any afternoon convection or sea-breeze cooling, and whether the heatwave warning holds through the daytime peak.[2][9] For on-chain traders, the contract settles in USDC, so the practical risk is binary around the observed max rather than the broader summer pattern, and there is limited reason to read it through BTC or ETH unless a wider risk-off move is affecting market-wide liquidity. Weather volatility in this setup is mostly local: a few degrees of cooling from cloud cover or showers can decide whether the station posts a qualifying maximum.[2][13][14]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

UK Frequently Asked Questions

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

What does a transaction cost on Polygon?

Polygon gas is typically under $0.01 per transaction. A full trade cycle (Approve + Order + Fill) totals around $0.03 — compared to $5-50 on Ethereum mainnet.

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%.