Highest temperature in Paris on June 28?

Platform comparison

Market context

The highest temperature recorded at Paris-Le Bourget Airport on 28 June 2026 will determine the outcome of this prediction market, with the current crowd-implied probability for a 28°C result sitting at 0% YES. On Polymarket, this contract trades as a conditional token on the Polygon network, settled in USDC, where traders are effectively betting against the 28°C threshold based on the prevailing on-chain pricing. The market resolves strictly via Wunderground data for the Paris-Le Bourget station, toggling between Fahrenheit and Celsius via the gear icon, making the on-chain mechanics a direct reflection of the real-world thermal event.

Historical precedents frame the current 0% probability as a rational market stance rather than an anomaly. France recently recorded its hottest day ever on 23 June 2026, with a national thermal indicator of 29.8°C and localized peaks exceeding 43°C, shattering records since 1947[2][7]. Paris itself has already broken its June temperature record, reaching 38.4°C earlier in the month, while forecasts suggested the capital could top 40°C mid-week[4]. Given that 28°C is significantly lower than these recent extremes, the market correctly prices the event as highly improbable, aligning with the record-breaking heat dome that has dominated Western Europe[3][8].

Traders should monitor the official heatwave schedules and any sudden meteorological announcements from Météo France, particularly as the settlement window closes on 28 June. The primary catalyst is the persistence of the unrelenting heat dome, which has already caused events like the Dior and Rick Owens show to be delayed due to temperatures reaching 44.3°C[5]. With spring 2026 confirmed as France’s warmest ever recorded, averaging 13.8°C, the thermal baseline remains exceptionally high[6]. Any deviation from this extreme pattern would be the only scenario altering the current pricing, but the on-chain data suggests the market expects temperatures to remain well above the 28°C threshold.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

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.

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.