Platform comparison
| Platform | YES odds | NO odds | Fee | KYC | Settlement | |
|---|---|---|---|---|---|---|
Polymarket (via Prediction Today) Pick polygram.ink (preferred broker) |
97% | 3% | 0% (USDC on-chain) | No-KYC up to $1,500 | USDC, auto via UMA oracle | Live odds → |
Polymarket (direct) polymarket.com |
97% | 3% | 0% | Geo-blocked in US/UK/EU | USDC, on-chain | Live odds → |
Kalshi kalshi.com |
— | — | Up to 7% per trade | US-only, KYC required | USD | Live odds → |
Betfair Exchange betfair.com |
— | — | 2-5% commission | Full KYC from first trade | GBP / EUR | Live odds → |
Manifold Markets manifold.markets |
— | — | Play-money (mana) | None — play-money | Mana (no cash-out) | Live odds → |
Outcome probabilities
Current market-implied probability for each outcome, from the live order book.
| Outcome | Probability |
|---|---|
| 26°C | 97% |
| 27°C | 4% |
| 21°C or below | 0% |
| 22°C | 0% |
| 23°C | 0% |
| 24°C | 0% |
| 25°C | 0% |
| 28°C | 0% |
| 29°C | 0% |
| 30°C | 0% |
| 31°C or higher | 0% |
Market context
Busan's August heat will determine this market's outcome, with the settlement hinging on the precise daily maximum recorded at Gimhae International Airport on 17 August 2026. The 0% crowd probability suggests traders are pricing in either extreme confidence in a specific temperature range or genuine uncertainty about which bracket will capture the day's peak. August typically brings Busan's most intense summer conditions, with daily highs regularly exceeding 30°C during the monsoon transition period.
Historical August records for Gimhae show temperatures frequently reaching 32–35°C, with occasional spikes above 36°C during particularly intense heat waves. The 2018 Korean heat wave saw Busan record 34.5°C on 17 August that year, whilst cooler Augusts have produced highs around 29–31°C. These precedents matter because the market's resolution depends entirely on Weather Underground's Daily Observations table at Gimhae—not summary figures—making consistency with historical station data critical for calibration.
Traders should monitor late July and early August 2026 weather patterns, particularly the position of the North Pacific high-pressure system and any tropical cyclone activity in the region, both of which significantly influence Busan's temperature extremes. The Korea Meteorological Administration's extended forecasts, typically issued 10 days ahead, will provide the clearest signal of whether August 17 falls within a heat-wave window or a more moderate spell. Station-specific data from Gimhae has occasionally diverged from city-centre readings, so historical variance between airport and urban measurements should inform range selections.
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
At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.
On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.
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 Prediction Today. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.
- What does Polymarket cost to trade?
- Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.
- 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%.
Trade Highest temperature in Busan on August 17? on Prediction Today
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