Highest temperature in Paris on July 7?

Platform comparison

Market context

The Paris-Le Bourget Airport is bracing for an intense heatwave on 7 July 2026, with temperatures expected to soar well above seasonal norms under a settling heat dome. Current short-range ensemble forecasts from major models indicate a high probability of a maximum temperature between 34–36°C, while some weather experts suggest the high could reach as much as 41°C on this day[1][2]. This real-world surge in heat directly contradicts the market’s current crowd-implied probability of 0% for the highest temperature being in the lowest range, as traders are instead pricing in outcomes centred around 33°C at 56% and 34°C at 26%[2].

Historical data frames this current probability as an outlier, given that July in Paris typically sees average highs of 26°C, with a recorded range of 20°C to 43°C since 1991[5]. The all-time monthly record for July stands at 43°C, set in 2019, and recent years have shown a warming trend with average highs increasing by 1–2 degrees Fahrenheit over the past decade[5]. The current heat dome pushing temperatures to 35–36°C this week aligns with these escalating norms rather than the cooler baseline the 0% probability implies, suggesting the market may be misreading the severity of the incoming conditions[1].

Traders must monitor Météo-France’s red heat wave alerts, which have been issued for 54 departments and indicate high temperatures persisting around the clock[7]. The immediate catalyst is the confirmed heat dome settling over Île-de-France, with peak temperatures near 36°C forecast for Tuesday and 35°C for Wednesday[1]. Officials are advising residents to avoid heavy exercise between 12:00 p.m. and 6:00 p.m. and to stay indoors during the hottest hours, while special cooling centres remain open in libraries and gyms[3]. The resolution source will be the highest temperature recorded for all times on 7 July at the Paris-Le Bourget station via Wunderground, so any late-afternoon spike could significantly alter the outcome[3].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Kalshi UK, which mirrors the Polymarket order book directly.

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 Kalshi UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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 Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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.