Highest temperature in Paris on June 28?

Platform comparison

Market context

The real-world event hinges on the highest temperature recorded at Paris-Le Bourget Airport on 28 June 2026, a date currently sitting in the final hours of its settlement window. With crowd-implied probability at 0% for a specific high range, the market reflects a near-certainty that conditions will not breach extreme thresholds, despite Europe’s ongoing heat emergency. This stance is stark when weighed against recent history: Paris hit 40.9°C on 24 June 2026, the hottest June temperature ever recorded for the city, while France’s national thermal indicator reached 29.8°C across 30 stations, with southern France peaking at 45.9°C [2][4][8]. Such extremes suggest that a 0% probability may be premature if the heatwave persists, as June 2026 has already shattered multiple records, including France’s hottest day ever [3][9].

Traders approaching this market programmatically should monitor real-time Wunderground feeds for the Paris-Le Bourget station, cross-referencing with Meteo-France alerts and regional heatwave advisories. The primary catalyst is the continuation of the current heatwave, which has forced early closures at the Louvre and Eiffel Tower due to record temperatures [5]. A key dependency is the timing of the daily peak, which typically occurs between 11:00 and 16:00 UTC; if the heatwave intensifies during this window, the 0% probability could shift rapidly. Recent news confirms France is under a major weather emergency with safety protocols urging indoor confinement during peak sun hours [1]. Any deviation from the current trend—such as a sudden cooling front or sustained high-pressure system—would directly alter the resolution outcome, making live data ingestion essential for conditional order execution.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Paris on June 28? 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

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

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.

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.