Highest temperature in Madrid on August 15?

Platform comparison

Market context

Madrid's highest temperature on 15 August 2026 will be measured at Adolfo Suárez Madrid-Barajas Airport and recorded in Weather Underground's Daily Observations table. The market currently prices a YES outcome at 2%, suggesting traders expect the temperature to fall below a specific threshold that day. Settlement hinges on the primary resolution source—WU's Daily Observations rather than the Day High & Low summary—a distinction that matters when station readings diverge.

August temperatures in Madrid historically cluster between 32–38°C, with extremes occasionally breaching 40°C during heat waves. The city's all-time August high stands at 42.2°C (recorded in 2003). A 2% probability implies the market is pricing in a low likelihood of an exceptionally hot day on that specific date, roughly equivalent to conditions outside the upper quartile of August heat events. This baseline reflects typical late-summer variability rather than anomalous atmospheric conditions.

Traders should monitor European summer weather patterns from July 2026 onwards, particularly Atlantic pressure systems and North African heat advection forecasts. Spain's national meteorological agency (AEMET) typically issues seasonal outlooks in June, and any signals of an exceptional heat dome would shift market pricing. Real-time catalysts include mid-August European weather model runs (available 10–14 days prior to settlement), which provide the most actionable data for conditional token positions on Polygon. The settlement window closes at 12:00 UTC on 15 August, allowing only morning observations to influence final resolution.

Methodology

We track Highest temperature in Madrid on August 15? 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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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 PolyGram. 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.