Highest temperature in Paris on July 16?

Platform comparison

Market context

Paris-Le Bourget Airport is set to record its peak temperature for 16 July 2026, with the market currently pricing a 0% chance that the outcome will fall outside the defined resolution ranges. Historical data from recent July mid-months in Paris shows temperatures frequently clustering between 32°C and 34°C, with 33°C appearing as the most common high in comparable years. This pattern aligns with the current frontrunner on Polymarket, where 33°C commands a 53% implied probability, while 32°C holds 30%, suggesting the crowd expects a warm but not extreme day.

Traders should monitor the Meteo France daily forecast and any upstream heatwave advisories issued for the Île-de-France region, as these often precede significant temperature shifts. A recent update from Meteo France indicates stable high-pressure conditions over western Europe, which typically sustains daytime highs in the low-to-mid 30s during mid-July [1]. The settlement relies exclusively on Wunderground’s recorded maximum for Paris-Le Bourget, so any discrepancy between forecast models and actual station readings could create arbitrage opportunities between Polymarket and Kalshi lines if the latter offers divergent odds on similar temperature bands.

The 0% current crowd-implied probability for the YES outcome likely reflects a misunderstanding of the market’s binary structure or a misalignment in how the question is framed across platforms. In contrast, the distribution across temperature ranges on Polymarket shows a clear consensus around 33°C, offering a more granular view than binary sportsbook-style lines. This divergence highlights how prediction markets can capture nuanced weather expectations that traditional binary contracts may miss, particularly when the underlying event is a specific temperature threshold rather than a simple yes-or-no outcome.

Sources: 1

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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

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 PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.