Highest temperature in Paris on July 9?

Platform comparison

Market context

The real-world event hinges on the highest temperature recorded at Paris-Le Bourget Airport on 9 July 2026, measured in degrees Celsius and resolved via Wunderground data. With the crowd-implied probability of a specific outcome sitting at 0%, the market currently reflects extreme uncertainty or a perceived impossibility of that particular temperature range occurring, despite France entering a persistent heatwave phase just days prior.

Historical precedents frame this probability sharply: Paris experienced peak temperatures near 40°C (104°F) during consecutive days in early July 2026, with Météo-France projecting highs up to 37°C (99°F) for the second heatwave starting mid-week [2][4]. Comparable cases from the 2026 heat dome show that mid-July highs in Paris routinely exceed 35°C, making temperatures around 32°C tolerable all day while 35°C remains manageable until early afternoon [3]. These records suggest the 0% probability may be a mispricing, as the thermal conditions align with ranges previously observed.

Traders approaching this programmatically should monitor Météo-France’s daily bulletins and the national thermal index, which surpassed the heatwave threshold on 6 July and is expected to persist until after 14 July [4]. Key catalysts include the scheduled duration of the current heatwave, which Météo-France states has no defined end yet, and dependencies on regional wind patterns that could push northern temperatures between 36°C and 38°C [4]. A recent report from Le Monde confirms the intensity and persistence of this extreme heat, noting that uncertainty remains high regarding its termination [4].

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 Kalshi Fees, 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.

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.