Highest temperature in Paris on July 4?

Platform comparison

Market context

Paris-Le Bourget is set to record its highest temperature on 4 July 2026, with the market currently pricing a 30°C outcome at 96% probability, while the 0% YES implied probability for any alternative suggests near-universal confidence in this specific range. Historical data frames this tight consensus: July in Paris typically sees average highs of 26°C, but heatwaves can push temperatures to 43°C, as recorded in 2019, though such extremes are rare and usually confined to southern regions like Landes, which hit 44.3°C recently [3][5]. The current 96% weighting on 30°C aligns with the upper end of typical July highs (77°F or 25°C) but remains well below the record 43°C, indicating traders view a moderate heatwave as the most likely scenario rather than an extreme event [2][3].

Traders should monitor the Met Office’s daily heatwave forecasts and Wunderground’s real-time updates for Paris-Le Bourget, as a sudden shift in atmospheric pressure or cloud cover could alter the temperature trajectory before the 12:00Z settlement window closes. Recent news highlights France’s vulnerability to record-breaking heat, with the Louvre and Eiffel Tower closing early during a 45.9°C spike in southern France, underscoring how quickly conditions can escalate [4][7]. While no specific announcement is pending for 4 July, the dependency on regional weather patterns means any deviation from the 30°C forecast—such as a stronger-than-expected heatwave—would be the primary catalyst for odds divergence across platforms. The current 0% YES probability for non-30°C outcomes reflects a lack of perceived risk, but historical volatility in July temperatures suggests traders should watch for sudden shifts in the Met Office’s guidance.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Paris on July 4? 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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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 Best Prediction Markets UK. 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.

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.