Platform comparison
| Platform | YES odds | NO odds | Fee | KYC | Settlement | |
|---|---|---|---|---|---|---|
Polymarket (via BTC Prediction) Pick polygram.ink (preferred broker) |
100% | 0% | 0% (USDC on-chain) | No-KYC up to $1,500 | USDC, auto via UMA oracle | Open live market → |
Polymarket (direct) polymarket.com |
100% | 0% | 0% | Geo-blocked in US/UK/EU | USDC, on-chain | Open live market → |
Kalshi kalshi.com |
— | — | Up to 7% per trade | US-only, KYC required | USD | Open live market → |
Betfair Exchange betfair.com |
— | — | 2-5% commission | Full KYC from first trade | GBP / EUR | Open live market → |
Manifold Markets manifold.markets |
— | — | Play-money (mana) | None — play-money | Mana (no cash-out) | Open live market → |
Outcome probabilities
Current market-implied probability for each outcome, from the live order book.
| Outcome | Probability |
|---|---|
| 36°C | 100% |
| 30°C or below | 0% |
| 31°C | 0% |
| 32°C | 0% |
| 33°C | 0% |
| 34°C | 0% |
| 35°C | 0% |
| 37°C | 0% |
| 38°C | 0% |
| 39°C | 0% |
| 40°C or higher | 0% |
Market context
Chongqing will experience peak summer heat on 14 August 2026, with the highest temperature recorded at Jiangbei International Airport Station determining the settlement outcome. The market resolves to a specific temperature range in Celsius, drawing data from Weather Underground's Daily Observations table rather than summary figures, a distinction that matters when intraday spikes occur between official recording intervals.
Chongqing's August climate sits within a narrow historical band. The city's average daily high in mid-August hovers around 32–34°C, though extremes have reached 40°C during intense heatwaves. The 0% crowd probability suggests traders are pricing in either exceptionally cool conditions or treating the market as illiquid. Comparable August readings from 2015–2023 show the station recording highs between 31°C and 39°C on this date, with only two instances exceeding 37°C. This historical clustering provides a baseline for assessing which temperature ranges carry genuine tail risk versus consensus expectations.
Monitoring China's meteorological forecasts and any issued heat warnings from the China Meteorological Administration will signal whether August 2026 develops anomalous conditions. Real-time atmospheric pressure systems tracking across the Yangtze River valley typically determine Chongqing's mid-August trajectory; El Niño or La Niña phase strength influences regional summer intensity. Settlement occurs at 12:00 UTC on 14 August, allowing traders to incorporate final 24-hour forecasts. USDC settlement mechanics mean positions can be hedged against broader macro moves if crypto volatility spikes during the resolution window, though weather outcomes remain independent of on-chain activity.
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
- What are crypto prediction markets?
- Crypto prediction markets are on-chain smart contracts where you buy YES or NO shares on a future crypto event (e.g. "BTC above $100k by year-end"). The market price between 0¢ and 100¢ is the implied probability.
- 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%.
Trade Highest temperature in Chongqing on August 14? on BTC Prediction
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