Highest temperature in Paris on July 20?

Platform comparison

Market context

Paris-Le Bourget is set to record its highest temperature on 20 July 2026, with forecasters warning of an intense heatwave pushing readings between 36°C and 39°C, potentially touching 40°C on some afternoons[4]. Despite this, the Polymarket contract for the “YES” outcome currently sits at 0% implied probability, while the 24°C range commands a 100% frontrunner status, suggesting traders are pricing in a significant divergence between live forecasts and the market’s conditional token distribution[1].

Historically, mid-July in Paris sees average highs of 25–27°C, but canicules routinely drive temperatures to 35–40°C for multiple days, especially in the middle of the month[2]. The current 0% pricing on the higher range appears inconsistent with these established patterns, where heatwaves have repeatedly breached 35°C in recent years, making the market’s stance on 24°C as the definitive outcome a notable outlier against comparable seasonal data.

Traders should monitor Météo-France’s latest advisories, which indicate the heatwave may persist beyond 14 July with no clear end date yet[5]. The settlement hinges on Wunderground’s daily record for Paris-Le Bourget, and any shift in Atlantic cooling forecasts—expected by the end of the current week—could alter the final temperature range[4]. With USDC settlements on Polygon, the market’s resolution depends entirely on this single data point, making real-time weather updates the primary catalyst for price movement.

Sources: 1 · 2 · 3 · 4 · 5

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

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

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi UK 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.