Platform comparison
| Platform | YES odds | NO odds | Fee | KYC | Settlement | |
|---|---|---|---|---|---|---|
Polymarket (via BTC Prediction) Pick polygram.ink (preferred broker) |
99% | 1% | 0% (USDC on-chain) | No-KYC up to $1,500 | USDC, auto via UMA oracle | Open live market → |
Polymarket (direct) polymarket.com |
99% | 1% | 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 |
|---|---|
| 15°C | 99% |
| 7°C or below | 0% |
| 8°C | 0% |
| 9°C | 0% |
| 10°C | 0% |
| 11°C | 0% |
| 12°C | 0% |
| 13°C | 0% |
| 14°C | 0% |
| 16°C | 0% |
| 17°C or higher | 0% |
Market context
Wellington’s temperature on 10 August will settle from the *highest reading* logged at Wellington Intl Airport, not the summary high shown elsewhere, so the key question is whether the day’s peak lands in the 10–12°C or 13–15°C band. August is typically Wellington’s coldest month, with long-run averages around 12°C for daily highs and many recent August peaks clustered in the low teens, which makes the market’s 0% YES pricing for a higher band look consistent with climatology rather than a view on a specific forecast spike.[5][8][17]
Comparable August histories point to a city that usually stays cool and changeable, with frequent wind and rain suppressing midday maxima. Recent Wellington August observations on Weather Underground and other history pages show highs commonly in the low-to-mid teens Celsius, while individual days can still briefly exceed that if sunshine and lighter winds align.[2][14] For an on-chain market settling in USDC, the relevant read-through is that this is a binary data-oracle event rather than a macro trade: the contract pays out on the recorded airport observation, so crowd pricing should mostly reflect the chance of a warm outlier, not broader crypto volatility.
The main catalysts are the day’s weather evolution and any forecast updates for Wellington, especially cloud cover, wind, and rain timing, because these determine whether the airport can reach a higher afternoon maximum. Timeanddate’s live historic page and Weather Underground’s daily observations are the practical references traders will watch as the day progresses.[3][14] Unless there is an unusual synoptic setup, the market is likely to stay anchored to seasonal norms; BTC or ETH moves matter only indirectly if they affect liquidity, funding, or whale positioning around the contract, not the weather outcome itself.
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.
- 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.
- 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 Wellington on August 10? on BTC Prediction
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