Highest temperature in Paris on August 20?

Platform comparison

Market context

On 20 August 2026, the highest temperature recorded at Paris-Le Bourget Airport will determine the settlement outcome of this market. The resolution hinges on the Daily Observations table from Weather Underground rather than summary figures, a distinction that occasionally produces material differences when intraday peaks occur outside standard reporting windows. Settlement occurs at 12:00 UTC on the same day, allowing traders a narrow window to react to final readings before USDC payouts execute on-chain.

Historical August temperatures at Le Bourget show a median high around 25–26°C, with extremes ranging from 18°C in cooler years to 37°C during heat waves. The 2003 European heat event saw Paris exceed 38°C; more recently, August 2022 peaked near 35°C. The 0% crowd probability suggests either extreme confidence in moderate conditions or insufficient liquidity to price tail scenarios. Given that one-in-ten August days at Le Bourget exceed 30°C, and one-in-twenty exceed 32°C, the current odds appear to underweight historical volatility.

Traders should monitor European weather forecasts from Météo-France and ECMWF model updates in the weeks preceding 20 August, particularly any signals of Atlantic blocking patterns or heat dome formation. Funding rates on temperature derivative contracts at crypto weather platforms may shift ahead of the settlement date if institutional flows detect model consensus shifts. Real-time Le Bourget station data availability on Wunderground remains critical; any platform outages or sensor recalibration could delay resolution confirmation.

Methodology

This page reads Highest temperature in Paris on August 20? on-chain. Polymarket's quote comes directly from the Polygon order book — the only comparable venue with on-chain settlement. Kalshi (USD, off-chain), Betfair (GBP/EUR, off-chain) and Manifold (play-money) are listed alongside for venue context. Every CTA routes to BTC Prediction, which mirrors the Polymarket order book directly.

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.

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No, Polymarket operates exclusively in USDC on Polygon. You can bridge BTC to USDC via an exchange or bridge service and deposit on Polygon — typically 10-30 minutes processing time.

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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%.