Pronóstico: Highest temperature in Paris on July 4?

Platform comparison

Market context

The underlying real-world event is a powerful heatwave pushing temperatures sharply higher across northern France on 4 July 2026, with Paris-Le Bourget Airport expected to reach 37°C by midday[1]. This contract currently trades at 0% YES on Polymarket, reflecting the crowd’s view that the temperature will not exceed the highest range threshold, despite the blistering conditions forecast[1]. On-chain, the market is settled in USDC on Polygon using conditional tokens, where liquidity providers and traders bet on the specific Celsius range that will contain the day’s peak reading.

Historical precedents frame how to interpret this near-zero probability: France recorded 44.3°C on 23 June 2026 during a historic European heatwave, and Paris itself hit 42.4°C on 25 July 2019[3][8]. Yet the current forecast for 4 July caps at 37°C, well below those extremes, suggesting the market correctly prices the event as unlikely to breach the top range[1]. Traders should note that while June 2026 saw peaks near 40°C, the July 4 forecast is notably lower, reinforcing the 0% valuation[2].

Key catalysts to watch include any sudden shifts in the heatwave’s intensity or official updates from Météo-France regarding temperature anomalies[2]. A recent Reuters report highlighted French weather agencies forecasting record highs of 40°C in late June, but the July 4 outlook remains distinct[5]. Traders must monitor Wunderground’s real-time data for Paris-Le Bourget, as the resolution hinges on the highest temperature recorded at any time on 4 July 2026[1]. Any unexpected cloud cover or rain could alter the peak, though dry conditions dominate the forecast[1].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Pronóstico: 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 Polymarket Qué Es, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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.

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.

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 Qué Es trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.