Highest temperature in Paris on July 7?

Platform comparison

Market context

Paris is bracing for an unprecedented heatwave on 7 July 2026, with meteorologists forecasting peak temperatures potentially reaching 41°C at the Paris-Le Bourget Airport Station. This extreme event, described by weather experts as a red-alert situation, involves scorching sunshine, dry conditions, and nights that stay above 28°C, creating a scenario where the daily high could shatter previous records for the region[1].

Historical data shows Paris recorded 42.4°C on 25 July 2019, the highest temperature ever in the Île-de-France region, suggesting that a 41°C peak is within the realm of possibility for this intense summer spell[8]. While the current prediction market implies a 0% probability for the highest temperature range, this stark divergence from the 41% chance traders assign to a 34°C peak on the following day (8 July) highlights a significant mispricing or a specific market assumption that the 7th will not breach the upper threshold despite the red alert[5].

Traders must monitor real-time updates from Meteo France and Wunderground, as the heatwave is expected to persist until at least 9 July with only a slight temperature drop[4]. The primary catalyst is the sustained high-pressure system driving extreme warmth across northern France, with officials urging residents to avoid heavy exercise between 12:00 and 18:00 due to the dangerous UV index and lack of nighttime cooling relief[1]. Any deviation in the forecast, such as the small chance of storms mentioned later in the week, could rapidly alter the settlement outcome, making the 0% market implied probability highly vulnerable to correction.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Paris on July 7? 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

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 Kalshi vs Polymarket. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.