Highest temperature in Paris on August 5?

Platform comparison

Market context

Paris’s highest temperature on 5 August will be set by the Paris-Le Bourget Airport station, with settlement based on the day’s peak reading in degrees Celsius. The crowd is currently assigning **0%** to the YES side, which is notably lower than the wider market colour: PolyBet’s contract ladder has the bulk of probability concentrated in the **28–29°C** band, with 28°C and 29°C each near the high-30s, while 30°C and above draw only small residual interest.[2]

That pricing sits broadly in line with the seasonal backdrop. Paris’s August average highs are usually in the mid-20s Celsius, with one forecast product showing around **24°C** for 5 August and another weather outlook pointing to about **29°C** on the day, so the distribution is still centred well below heatwave territory.[8][11][12] Recent French summers have shown that extremes can arrive quickly, however: Reuters reported in June that the national weather service was warning of record-high temperatures, and France later logged an all-time national high of 44.3°C during the June heatwave.[15][13]

For traders, the key catalysts are the morning and early-afternoon observations at Le Bourget, because a late-day spike is what typically moves the top-of-day number for this contract. The main dependency is whether Paris stays in the dry, sunny pattern flagged in local forecast coverage, which called for around **29°C** on Wednesday, versus any cloud, rain, or sea-breeze moderation that could cap the peak closer to the high-20s.[12][11] In cross-platform terms, the sportsbook-style market appears to price a centre mass around 28–29°C, while the prediction market’s **0%** YES implies either a stale, mis-set, or extremely bearish view relative to those temperature lines.[2]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Paris on August 5? 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 Best Prediction Markets. 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.

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.