Highest temperature in Paris on August 15?

Platform comparison

Market context

The market is pricing a 1% probability that Paris-Le Bourget Airport will record a peak temperature of 40°C or higher on 15 August 2026. This represents an extreme heat event by French standards, requiring sustained atmospheric conditions well above the region's typical August average of 25°C. The settlement hinges on Weather Underground's Daily Observations table rather than summary figures, a distinction that matters when automated stations report sub-hourly peaks that may not appear in rounded daily summaries.

Historical context shows Paris experiences temperatures exceeding 40°C roughly once per decade. The 2003 European heat wave saw Paris reach 40.3°C on 4 August, whilst more recent summers including 2022 peaked around 38–39°C. August 15 specifically falls within the warmest fortnight of the year, but achieving 40°C requires either an exceptional heat dome or an unusual atmospheric pattern. The current 1% pricing reflects this rarity—such events are plausible but require multiple meteorological factors aligning simultaneously.

Traders monitoring this contract should track European summer weather patterns from June 2026 onwards, particularly jet stream positioning and Atlantic blocking systems that can stall heat over continental Europe. Météo-France's seasonal outlooks and real-time forecasts from mid-August will provide actionable signals. The USDC settlement on Polygon occurs after 12:00 UTC on 15 August, allowing traders to adjust positions based on morning forecasts and early-day temperature readings before final resolution.

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to PolyGram, which mirrors the Polymarket order book directly.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

UK Frequently Asked Questions

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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%.