Highest temperature in Busan on August 6?

Platform comparison

Market context

Polymarket is pricing this Busan temperature contract at **0% YES** today, even though the event is a simple one: the highest reading at Gimhae Intl Airport Station on 6 August will be matched to a Celsius range for settlement in conditional tokens on Polygon, with USDC at risk for holders of the winning outcome. With the settlement window ending at 12:00 UTC, the market is effectively asking whether a late-morning or early-afternoon spike can move the airport station into one of the listed bands; until then, every tick in the order book reflects traders’ view of the day’s maximum rather than the full-day average.

Recent heat across south-eastern South Korea is the main comparison point. Busan set a 122-year temperature record at 38.8°C on 30 July, while nearby Yangsan reached 42.5°C on 2 August, the highest temperature ever recorded in Korea’s modern observation period. That matters because Busan has already shown it can overshoot seasonal norms during this spell, but it also shows how quickly extreme inland readings can differ from coastal Busan and from the airport station specifically. Seasonal guides still put Busan’s August highs around the upper 20s to around 30°C, which helps explain why the current market is anchored near the lower-probability tails rather than the hottest bands.

A trader should watch whether the heatwave persists and whether local forecasts keep Busan in the low-to-mid 30s, since that is the range implied by recent reporting. Chosun reported on 5 August that Busan and Ulsan were expected to reach about 33°C on Thursday, while nearby cities faced somewhat higher ceilings, and that kind of forecast can matter more than the broader regional record because the market settles on the airport station’s observed maximum, not the citywide headline. On Polymarket, that means the contract can reprice quickly if morning guidance shifts, if cloud cover or sea breeze limits coastal heating, or if conditions stay hot enough for a brief midday surge.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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.

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%.