Highest temperature in Paris on May 31?

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Active sub-markets

Market context

On 31 May 2026, the highest temperature recorded at Paris-Le Bourget Airport will fall into one of several defined ranges. Polymarket currently prices all temperature brackets at 0% YES, reflecting the market's nascent state and the settlement window's distance. The contract resolves against Wunderground historical data for that specific date, with traders required to verify readings through the platform's temperature toggle between Celsius and Fahrenheit. USDC settlement on Polygon means positions remain conditional tokens until the market closes at 12:00 UTC on the resolution date.

Paris's late May weather typically ranges between 18–25°C, though heat waves have pushed highs into the low 30s during this period. The city recorded 32.3°C on 31 May 2015 and 29.8°C on 31 May 2019, establishing that temperatures above 28°C occur roughly once per decade on this calendar date. Historical volatility suggests the most probable outcome clusters around 20–26°C, with extreme heat (above 30°C) representing a tail event rather than baseline expectation.

Traders monitoring this contract should track European seasonal forecasting updates released in April and May 2026, particularly from Météo-France and the European Centre for Medium-Range Weather Forecasts. La Niña or El Niño conditions developing through early 2026 will influence continental pressure patterns and jet stream positioning. Urban heat island effects at Le Bourget, located north-east of central Paris, typically suppress recorded temperatures by 1–2°C relative to the city centre, a factor worth accounting for when evaluating range probabilities.

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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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.

Is this market available outside the US?

Kalshi UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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 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.