Highest temperature in Paris on July 20?

Platform comparison

Market context

Paris is about to face an intense heatwave with temperatures expected to soar between 36°C and 39°C, potentially climbing to 40°C on some afternoons, a level the city has only hit a few times in its history [3]. This extreme forecast directly contradicts the current crowd-implied probability of 0% YES for the highest temperature on 20 July 2026, suggesting the market is mispricing the likelihood of record-breaking heat.

Historically, July is Paris’s hottest month, with average highs of 25–27°C, but canicules can push temperatures to 35–40°C for days, especially in mid-July [2]. The current frontrunner on Polymarket is 24°C at 100%, yet recent data shows France is facing a renewed heatwave with temperatures reaching 40°C, and Météo-France does not see an end to it until after 14 July [3][7]. This historical precedent of sustained mid-July heatwaves frames the 0% probability as a significant outlier against observed weather patterns.

Traders should monitor Météo-France’s orange or red heat alert updates, as a renewed alert cannot be ruled out and could confirm peak temperatures exceeding 35°C [5]. The settlement relies on Wunderground data from Paris-Le Bourget Airport, so any official temperature logs posted there will determine the outcome. With cooler Atlantic air forecast only by the end of the week, the window for 40°C peaks remains open through 20 July, making the current pricing vulnerable to rapid correction as forecast details solidify [3].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Polymarket Scam?, which mirrors the Polymarket order book directly.

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

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.

Do I need to KYC for this market?

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