Pronóstico: Highest temperature in Paris on July 12?

Platform comparison

Market context

Paris faces a critical heat check on 12 July 2026, as the city’s highest temperature at Paris-Le Bourget Airport will determine the outcome of this USDC-settled Polymarket contract. The crowd currently prices a YES outcome at 0%, implying near-total certainty that the temperature will fall outside the specific range being wagered on, despite forecasts suggesting July highs in Paris could reach 73° to 102°F (23° to 39°C) [1]. This extreme pessimism contrasts sharply with the 2026 European heatwaves, where Météo-France recorded France’s hottest day since 1947 on 23 June, with Pissos hitting 44.3°C and Paris’ Charles de Gaulle Airport reaching 44°C (104°F) [3][4].

Traders should monitor the tail end of the powerful heatwave forecast to hit France in early July, which meteorologists expect to last 7 to 10 days and potentially push daytime highs to 42°C in southern regions before affecting the north [2]. While the hottest spots are predicted in Marseille, Lyon, and Toulouse, northern areas including Paris are expected to feel significant heat, with nighttime temperatures staying above 25°C and offering little cooling [2]. The settlement depends entirely on the Wunderground record for Paris-Le Bourget, meaning any late-stage shift in the heatwave’s trajectory toward the capital could invalidate the current 0% pricing before the 2026-07-12T12:00:00Z deadline.

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

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.

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 Polymarket Qué Es. 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.

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.

Do I need to KYC for this market?

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