Highest temperature in Paris on June 30?

Platform comparison

Market context

On 30 June 2026, Paris-Le Bourget Airport will record its peak temperature for the day, a metric that determines the outcome of a prediction market where the crowd currently assigns zero probability to any outcome above the baseline. This real-world event hinges on precise meteorological data from Wunderground, capturing the highest temperature in degrees Celsius across all hours of that specific date.

Historical context frames the current 0% probability as a mispricing, given that recent heatwaves have shattered June records across western Europe. In late June 2026, Paris hit 40.9°C at Charles de Gaulle Airport, while France’s national thermal indicator reached a record 29.8°C, with temperatures soaring to 104°F at the airport on 24 June and 102°F on 25 June[2][4][8]. The market’s frontrunner is now 28°C at 51%, suggesting traders are recalibrating based on these unprecedented highs, which make a 0% probability for higher ranges statistically untenable[1].

A power-user approaching this programmatically would monitor real-time weather feeds and forecast updates for the Paris region, as the catalyst is the persistence of the current heat dome. Recent reports confirm red heat alerts remain active across northern Spain and parts of the UK, with temperatures potentially reaching 42°C in the Basque Country, indicating the heatwave is moving east and south[2][4]. Traders should watch for official announcements from Meteo-France regarding temperature thresholds, as the dependency is the sustained intensity of this unrelenting heat event, which has already set multiple all-time records[2][5].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Paris on June 30? 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

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 Polymarket App 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.

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 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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket App UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.