Highest temperature in Paris on July 5?

Platform comparison

Market context

The real-world event driving this contract is the daily maximum temperature recorded at Paris-Le Bourget Airport on 5 July 2026, with the market asking whether that peak will hit exactly 30°C. Current crowd-implied probability sits at 0% for a YES outcome, yet cross-platform data from Lines.com shows a divergent 44.5% implied probability for the 30°C bucket, suggesting a meaningful gap between prediction-market sentiment and sportsbook pricing. Historical context frames this divergence: France has experienced severe heatwaves in 2026, with temperatures reaching 35–38°C in June and peaks of 40°C recorded in Paris, while July averages for the region hover near 28.4°C, indicating that a 30°C peak is plausible but not guaranteed [3][4].

Traders must monitor the next Météo-France or ECMWF medium-range forecast update, as the contract resolves within 48 hours and is highly sensitive to model shifts. Recent news confirms an extended, severe heatwave is impacting France, with temperatures likely to rise further through the weekend, and continued hot afternoons under clear skies are expected [3][2]. The catalyst for a price move will be any official announcement narrowing the modal peak toward the low thirties, which could explain the fresh capital flowing into the 30°C outcome on alternative platforms [1]. With ten alternative temperature buckets counting as NO, the probability mass is spread thin, making the next forecast update the critical dependency for resolution.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Paris on July 5? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Best Prediction Markets UK, which mirrors the Polymarket order book at 0% fees.

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

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.

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.