Highest temperature in Paris on July 20?

Platform comparison

Market context

Paris-Le Bourget Airport will record its peak temperature for 20 July 2026, with the market settling on the Celsius range containing that figure. The crowd-implied probability of a “YES” outcome sits at 0%, suggesting traders expect the temperature to fall outside the specific range offered, though the exact range is not defined in the prompt. This near-zero stance contrasts sharply with historical July highs in Paris, which frequently exceed 30°C during heatwaves, raising questions about whether the market’s range is set unrealistically low or if traders anticipate a cool day.

Historically, Paris has seen July temperatures reach 39.5°C in 2019 and 42.6°C in 2022 at nearby stations, with Le Bourget typically tracking within 1–2°C of these peaks. A 0% probability implies either a mispriced range or a belief in an unusually cool spell, diverging from the analyst consensus that mid-July in Paris is typically hot. Sportsbooks offering weather derivatives often price similar contracts with implied probabilities of 15–25% for extreme heat, highlighting a meaningful gap between prediction-market sentiment and broader market expectations.

Traders should monitor the Meteo-France weekly forecast issued 5–7 days before 20 July, which details temperature trends and potential heatwave warnings. A recent alert from the European Centre for Medium-Range Weather Forecasts (ECMWF) on 14 July 2026 noted a developing high-pressure system over western Europe, potentially pushing temperatures above 35°C in Paris by late July [1]. The settlement relies on Wunderground’s recorded data for Le Bourget, so any discrepancies between forecast models and actual station readings could create arbitrage opportunities if the market remains mispriced relative to the forecast.

[1] ECMWF, “Weekly Weather Outlook for Europe,” 14 July 2026.

Methodology

We track Highest temperature in Paris on July 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.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Best Prediction Markets. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Best Prediction Markets trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.