Highest temperature in Paris on July 26?

Platform comparison

Market context

Paris’s highest temperature on 26 July will be set by the Paris-Le Bourget Airport reading in the Wunderground daily history page, so the relevant number is the single daily maximum rather than an hourly average or city-wide forecast. For a programmatic workflow, the cleanest approach is to monitor the station history output near the settlement cut-off and map the observed peak into the market’s Celsius bands; if the page updates late, the final print can move even after the day’s general weather looks settled.

The current 0% YES is only sensible if the market’s YES threshold is in a hotter range than the expected outcome. July in Paris is typically warm but not extreme, with highs around 25°C and many rainy days, while one July forecast source for Paris flagged a notably hotter spell with temperatures around 32.4°C early in the month and the possibility of much higher values during a heatwave. That makes the distribution skew sensitive to synoptic shifts: a brief Atlantic cool-down, cloud cover, or convection can cap the daily high well below the sort of upper-band outcome that a trader may be assuming from headline heatwave chatter.[1][2][3]

The main catalysts are therefore the short-range forecast updates, any French heat alerts, and the timing of the strongest afternoon heating before the 12:00 UTC settlement window closes. Power users watching this through bots or conditional orders should key off the nearest published forecast cycle rather than a single long-range outlook, because Paris heat outcomes can change materially with cloud, wind, or storm risk on the day. If the hottest part of the afternoon is expected after the market’s cut-off, that matters less than any warmth already locked in by midday UTC.[1][3][4]

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

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

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.

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.