Highest temperature in Paris on August 3?

Platform comparison

Market context

Paris’s highest temperature on 3 August will be set by the Paris-Le Bourget Airport Station, with the market resolving on the day’s peak Celsius reading from Wunderground. Polymarket’s current book is clustered around **35°C** at 38%, then **36°C** at 29% and **34°C** at 20%, which implies a fairly tight distribution rather than a broad heat-risk trade.[1]

That profile sits between normal August Paris weather and the recent run of extreme European heat. Long-run August norms for Paris are far lower, with average highs around the low-to-mid 20s Celsius, while current monthly forecasts point to a much warmer range, roughly 23°C to 31°C depending on the source and forecast horizon.[13][16][2] The market’s 35°C-centred pricing is therefore closer to an elevated-heat scenario than to climatology, but it is still not pricing a strong probability of an outright upper-tail print above 37°C; only a small fraction of the book sits there.[1]

For traders comparing venues, the main distinction is that Polymarket is giving a live probability distribution across temperature bands, while a sportsbook-style line would typically be expressed as an over/under or threshold price rather than a full outcome ladder. In practice, the most important catalysts are the morning and early-afternoon forecast updates for Île-de-France, any newly issued heat advisories, and whether cloud cover or showers clip the day’s maximum at Le Bourget. Recent reporting on France’s repeated 2026 heatwaves and late-July European heat anomalies matters because it supports the idea of persistent warm-air setup, but the contract ultimately settles on a single station reading rather than headline national temperatures.[18][20][12]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Paris on August 3? 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

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

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

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.

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