Highest temperature in Paris on July 4?

Platform comparison

Market context

On 4 July 2026, Paris-Le Bourget Airport will record its highest temperature for the day, a single real-world data point that determines the outcome of a prediction market. In this context, a YES share pays out if the temperature lands in a specific range (here, exactly 30°C), while a NO share pays out for any other outcome. The current crowd-implied probability of 0% for YES suggests traders overwhelmingly doubt the temperature will hit precisely 30°C, likely expecting it to be higher.

Historical July heat in Le Bourget typically sees highs between 25°C and 34°C, with an average of 29°C, but recent 2026 forecasts indicate a powerful heatwave pushing temperatures well above seasonal norms. A YouTube weather alert for 3–4 July 2026 predicts highs of 36–37°C, with morning lows near 23°C and minimal overnight cooling, framing the 0% YES probability as a rational response to extreme heat rather than a market error[2].

Traders should monitor Meteo France’s ongoing heatwave statements and daily temperature updates from Wunderground, the official resolution source. A Reuters report from 19 June 2026 confirmed a severe, extended heatwave already hitting record highs of 35–40°C across France, reinforcing expectations that 4 July will exceed 30°C[8]. With dry conditions, intense UV, and no rain expected, the catalyst for any shift in probability would be an unexpected advection of cooler maritime air, which current guidance does not anticipate[2][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 Prediction Market UK, 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.

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 Prediction Market 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.