Highest temperature in Paris on July 2?

Platform comparison

Market context

The underlying event is the highest temperature recorded at Paris-Le Bourget Airport on 2 July 2026, a date that historically sits within Paris’s warm summer window but remains far from the city’s peak heat extremes. Long-term averages suggest daytime maximums of 24°C in Paris during July, with roughly eight hours of daily sunshine and moderate rainfall across the month[1]. While Paris has seen temperatures above 40°C only three times, the record of 42.6°C was set on 25 July 2019, not in early July[2]. This historical framing makes the current crowd-implied probability of 0% for any temperature above 40°C appear consistent with past patterns, as early July has never produced record-breaking highs in the capital.

Traders should monitor Météo-France’s daily forecasts for the Paris region, particularly any announcements of tropical nights or influxes of warm air from North Africa, which have driven recent heat spikes across western Europe[2]. A second heatwave is already projected to begin mid-June, with peaks of 40°C anticipated on 21 June in the Paris region, though temperatures may drop slightly by late June before rising again[2]. Recent coverage from Le Monde confirms that France is bracing for exceptional heat, with forecasts of 34°C to 38°C across the country and potential 40°C peaks coinciding with the summer solstice[2]. No major divergence exists between sportsbook lines and prediction-market implied probabilities, as both reflect the low likelihood of extreme heat on this specific date, aligning with analyst consensus that early July remains a moderate thermal period for Paris.

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

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.

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.