Highest temperature in Paris on July 4?

Platform comparison

Market context

The Paris-Le Bourget Airport is bracing for a scorching heatwave on 4 July 2026, with forecasts predicting a midday high of 37°C, making it one of the hottest days of the summer so far[1]. This contract currently prices at 0% YES on Polymarket, reflecting the crowd’s certainty that the temperature will not land in the specific range being wagered on, despite the extreme heat expected[2]. On-chain, traders are using USDC on the Polygon network to buy conditional tokens, betting on the precise resolution source from Wunderground rather than the abstract notion of a hot day[2].

Historical precedents frame this probability sharply: France recorded its hottest day ever on 23 June 2026, with temperatures reaching 44.3°C in Landes, while the national thermal indicator hit 29.8°C[3][5]. Paris has also experienced unprecedented heat streaks, including a May 2026 high of 37.8°C in southwestern parts, suggesting that 37°C is well within the realm of recent extremes rather than an anomaly[7]. The current 0% price implies the market believes the range being wagered on is too narrow or misaligned with these documented peaks, given that July 3–4 conditions are nearly identical to the previous day’s intensity[1].

Traders should watch for real-time updates from Météo-France and Wunderground as the settlement window closes at 12:00 UTC on 4 July, since the resolution depends entirely on the highest recorded temperature for all times on that day[1]. A recent NBC News report confirmed that a severe heatwave continues to blister western Europe, with authorities issuing red heat warnings and reporting drownings linked to the oppressive heat[3]. The key dependency is the exact timestamp of the peak temperature, as any deviation could shift the outcome, and the market’s 0% stance suggests the crowd expects the temperature to exceed the wagered range significantly[1][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 PolyGram, 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

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 PolyGram. 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.

Do I need to KYC for this market?

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