Highest temperature in Paris on June 28?

Platform comparison

Market context

The real-world event in question is the peak temperature recorded at Paris-Le Bourget Airport on 28 June 2026, a specific meteorological data point that will determine the outcome of a prediction contract. While the current crowd-implied probability for a "YES" outcome sits at 0%, this figure diverges sharply from the trader consensus on Polymarket, where 99.9% of volume backs the 31°C range, reflecting a tight model agreement on a cooling trend despite residual uncertainty over the precise peak[1].

Historical context frames this probability against Paris’s typical June highs, which average between 69°F and 74°F (20.5°C to 23.5°C) and rarely exceed 84°F (29°C), though extreme outliers have occurred, such as the 42.4°C record in Paris during July 2019 and the 35.7°C peak recorded south of London in June 2024[2][4][8]. The current market pricing suggests a significant deviation from these recent extremes, aligning more closely with the average shortwave solar energy levels that remain constant throughout the month at approximately 6.4 kWh[2].

Traders should monitor the Met Office’s daily forecasts for France, which indicate conditions are expected to improve by Friday, potentially suppressing peak temperatures below the 31°C threshold that dominates current odds[3]. The primary catalyst remains the official Wunderground data release for Paris-Le Bourget, which will serve as the definitive resolution source, while any sudden shifts in regional heatwave alerts from the French government could rapidly alter the implied probability before the settlement window closes on 28 June 2026[9].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Paris on June 28? 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 Best Prediction Markets. 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.

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.