Highest temperature in Paris on August 14?

Platform comparison

Market context

Paris-Le Bourget Airport will record a daily high temperature on 14 August 2026, measured against the Daily Observations table on Weather Underground. The market currently prices at 0% YES, meaning traders are assigning negligible probability to any specific temperature range materialising on that date. This reflects the inherent uncertainty of weather forecasting eighteen months ahead, where deterministic models lose predictive power beyond a fortnight. On Polygon, conditional tokens representing each temperature bracket trade at valuations reflecting this consensus dismissal, though the USDC liquidity pool remains shallow given the settlement window's distance.

Historical August temperatures at Le Bourget show a median daily high around 25–26°C, with extremes ranging from 13°C to 37°C across the station's records. The 2003 European heat wave saw Paris reach 40°C, though such events remain statistical outliers. Recent summers have trended warmer; 2022 and 2023 both recorded August highs exceeding 30°C at the airport. These precedents suggest that mid-range brackets (24–28°C) carry the highest base-rate probability, yet the market's current pricing structure may not yet reflect this distributional reality.

Traders should monitor long-range climate forecasts released by Météo-France and the European Centre for Medium-Range Weather Forecasts (ECMWF) as August 2026 approaches. Seasonal anomaly patterns—particularly Atlantic oscillation indices and sea-surface temperatures in June and July 2026—will sharpen probability estimates. The resolution mechanism's reliance on Weather Underground's Daily Observations table rather than official Météo-France records introduces a minor technical dependency worth verifying before substantial position-taking.

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

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

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%.