Highest temperature in Paris on August 3?

Platform comparison

Market context

The event is the hottest temperature measured at Paris-Le Bourget Airport on 3 August 2026, with settlement based on the day’s maximum reading in Celsius from Wunderground. A **YES** share pays out if the final result falls in the specified temperature range for that day, while a **NO** share does not; in practice, the market is pricing whether the airport’s peak temperature lands in an exact band rather than just being broadly hot. Paris’s usual August daytime maximum is much lower, around the low-to-mid 20s Celsius, so the settlement depends on whether a one-day spike or a more ordinary summer pattern dominates.[13][16]

The current crowd-implied probability of **1% YES** points to an outcome that traders see as very unlikely under normal August conditions. That reading is consistent with climatology: historical August highs in Paris are far below the upper-30s or 40°C levels, although recent summers have shown that extreme heat can still produce sharp, short-lived jumps above seasonal norms.[13][18] For a new reader, the key point is that prediction markets are not forecasting averages; they are pricing a single observed reading at one station on one day, which makes the exact hour of peak heat important.

The main catalysts to watch are the near-term weather model runs, any French or regional heat alerts, and the timing of the hottest part of the day relative to the settlement window. Paris heat can be driven by continental high-pressure systems, southerly airflows, and strong sunshine, while cloud cover, rain bands, or a frontal passage can cap the afternoon maximum quickly. Recent reporting has also shown that France can move into severe heatwave conditions with little lead time, so traders will be watching updated forecasts rather than relying only on long-run averages.[20][17]

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 Prediction Market UK. 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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Prediction Market UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.