Highest temperature in Paris on August 6?

Platform comparison

Market context

Polymarket is pricing this Paris temperature contract at **0% YES**, even though the market’s own current lead outcome is 26°C at 64%, with 25°C next at 29%, so the listed crowd view is not aligned with the “YES” framing of the contract. On Polymarket, traders are holding USDC on Polygon through conditional tokens, so the contract only pays out according to the final Wunderground reading for Paris-Le Bourget Airport Station, not the citywide feel or an early forecast snapshot.[1]

The useful historical guide is that Paris in August usually sits in the mid-20s Celsius, which makes a sub-25°C outcome plausible only if cloud, rain, or a cooler Atlantic pattern suppresses the afternoon high. Recent summer heat in France has also shown how quickly readings can jump when hot air masses settle over northern France: Paris reached 40.9°C during the June 2026 heatwave, while the country as a whole posted record-breaking extremes, reminding traders that late-summer temperature tails can be wide even when the seasonal norm is moderate.[2][3][10]

For a hands-on Polymarket user, the main catalysts are the official afternoon forecast updates, any heat or thunderstorm advisories, and the final station datapoint published by Wunderground before the next day’s reading appears. Polymarket says revisions to temperatures inside the settlement window are counted until the first datapoint for the following date is published, so the live value at Paris-Le Bourget matters more than headlines or a general Paris forecast.[1]

Sources: 1 · 2 · 3 · 4 · 5

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

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

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.