Highest temperature in Paris on May 31?

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Active sub-markets

Market context

The Paris-Le Bourget Airport weather station will record a daily maximum temperature on 31 May 2026, with traders currently assigning zero probability to any outcome—a reflection of the market's nascent stage rather than genuine certainty about the forecast. May in the Paris region typically sees highs between 18°C and 23°C, though late-spring heat waves occasionally push readings into the upper 20s or low 30s. The 0% crowd probability suggests minimal trading activity and no consensus formation yet, leaving substantial room for calibration as the settlement date approaches.

Historical data from Paris-Le Bourget shows May 31st temperatures have ranged from around 15°C on cooler years to 28°C during warmer springs. The station's 30-year average for late May sits near 20°C, but individual daily extremes vary considerably depending on Atlantic weather patterns and high-pressure systems tracking across northern Europe. Recent springs (2022–2025) have shown increasing volatility, with several years recording unseasonably warm conditions by month's end. Traders should recognise that the current flat probability reflects absent liquidity rather than predictive insight; early positioning in ranges around 20–24°C would capture the historical modal outcome, whilst higher ranges (25°C+) remain underexplored despite their plausibility during anomalous warm patterns.

The key dependency is the European weather forecast window, which typically gains reliable detail 10–14 days before settlement. Météo-France and ECMWF model runs in mid-May will signal whether Atlantic blocking patterns or Mediterranean heat advection might elevate temperatures above the seasonal norm. Traders should monitor spring weather trend reports from March onwards, as persistent warmth or cold patterns established earlier in the season often persist into early June.

Methodology

We track Highest temperature in Paris on May 31? 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

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 Who Will Win 2026?

Zero. Who Will Win 2026 routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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.

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.