Highest temperature in Paris on July 13?

Platform comparison

Market context

On 13 July 2026, the highest temperature recorded at Paris-Le Bourget Airport will determine the outcome of a weather prediction market, where a YES share pays out if the temperature falls within a specific range and a NO share does not. The market currently assigns just a 1% probability to the YES outcome, reflecting traders’ view that extreme heat is unlikely for this date.

Historically, Paris has seen July highs around 34–35°C, with the city’s all-time record of 42.4°C set on 25 July 2019[3]. The current market frontrunner is 34°C at 46%, followed by 35°C at 28%, suggesting traders expect typical summer warmth rather than record-breaking heat[1]. France’s national record of 45.9°C occurred in southern Gallargues-le-Montueux, not Paris, underscoring regional variation[2].

Traders should monitor Météo-France’s heat alerts and daily temperature forecasts, as red alerts have previously preceded extreme conditions[10]. With a red heat wave alert already issued for 54 departments as of late June 2026, any escalation in warnings ahead of 13 July could shift probabilities[10]. The settlement relies on Wunderground’s recorded maximum for Paris-Le Bourget, so real-time updates from that station will be the final catalyst[1].

Sources: 1 · 2 · 3 · 4 · 5

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

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 Prediction Market UK. 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.

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.

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.