Highest temperature in Paris on May 26?

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Active sub-markets

Market context

On 26 May 2026, the highest temperature recorded at Paris-Le Bourget Airport will settle this market into one of several temperature bands. The current Polymarket pricing reflects near-zero conviction across all outcome ranges, suggesting traders are either awaiting clearer seasonal forecasts or treating late-May Parisian weather as genuinely uncertain. Settlement hinges on Wunderground's historical data feed for that specific station, with the window closing at midday UTC—meaning any temperature spike in the morning hours counts toward resolution.

Historical May weather at Le Bourget shows considerable variability. The station's records indicate late-May highs typically range between 18°C and 24°C, though anomalous heat events have pushed readings above 28°C in roughly one year per decade. The 2022 European heatwave saw Paris exceed 30°C in late May, whilst cooler springs have produced highs below 16°C. This 12–15°C spread between extreme outcomes explains why the market currently shows 0% probability stacked into any single band—the underlying event genuinely permits multiple plausible outcomes without obvious favourites.

Traders monitoring this contract should watch European weather pattern forecasts from late April onwards, particularly Atlantic pressure systems and high-altitude blocking patterns that determine whether warm continental air reaches northern France. Météo-France's extended outlooks, typically issued four to six weeks ahead, will provide the first substantive signal. Additionally, any anomalous warming across western Europe in early May could shift conditional token valuations on Polygon, as near-term weather models gain predictive power closer to the settlement date.

Methodology

We track Highest temperature in Paris on May 26? on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

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?

On Kalshi UK, which mirrors the Polymarket order book at 0% fees. 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 it cost to trade on Kalshi UK?

Zero. Kalshi UK routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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.