Highest temperature in Paris on August 20?

Platform comparison

Market context

The market concerns the highest temperature recorded at Paris-Le Bourget Airport on 20 August 2026, with settlement based on Weather Underground's Daily Observations table rather than summary figures. The crowd currently implies 0% probability across all temperature ranges, suggesting either insufficient liquidity or genuine uncertainty about which bin will contain the day's peak reading. Resolution depends on precise instrumental data from a single monitoring station rather than broader city-wide measurements, which narrows the scope considerably.

August temperatures at Le Bourget historically cluster between 18°C and 28°C, with extreme heat days (above 30°C) occurring roughly once per decade. The 2003 European heat wave saw Paris reach 40.3°C, though such outliers remain statistically rare. Recent Augusts have tracked closer to 22–26°C ranges. The absence of crowd probability suggests traders may be waiting for seasonal forecasts closer to the date, or the market lacks sufficient trading volume to establish meaningful odds. Comparable weather markets on other platforms typically show non-zero probabilities across multiple temperature bands even for distant dates.

Traders should monitor European summer weather patterns and any significant climate anomalies emerging in early 2026. The Met Office and Météo-France publish extended-range forecasts three to four weeks ahead, which would provide the first concrete signals about whether August 2026 tracks toward typical or exceptional conditions. Any major atmospheric drivers—persistent high-pressure systems, Atlantic storm tracks, or solar activity patterns—would materialise in forecasts by late July. The settlement window closes at midday on the event date, allowing only morning observations to influence final resolution.

Methodology

We track Highest temperature in Paris on August 20? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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.

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 does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

What are the best prediction markets for UK traders in 2026?

For UKGC-regulated markets: Betfair Exchange (sports, politics) and Smarkets (sports, politics, lower commission than Betfair). For broader global event prediction: Polymarket (deepest liquidity, 0% fee, USDC settlement). For US-regulated option: Kalshi (USD, limited UK payment options). Most serious UK traders use a combination of Betfair for regulated sports and Polymarket for broader markets.