Highest temperature in Madrid on July 25?

Platform comparison

Market context

Madrid's highest temperature on 25 July 2026 will be measured at Adolfo Suárez Madrid-Barajas Airport Station and recorded via Wunderground historical data. The market resolves to a specific temperature range, with the 3% implied probability suggesting traders view an extreme heat outcome as unlikely relative to typical July conditions in the Spanish capital.

Historical July temperatures at Madrid-Barajas show a median high around 32–34°C, with record highs exceeding 40°C occurring in roughly one in twenty summers. The 2022 heatwave pushed Madrid to 40.5°C in mid-July, whilst the 2003 European heat event saw temperatures breach 40°C across multiple days. These precedents establish that whilst extreme heat is plausible, it remains a tail-event scenario. The current 3% probability reflects baseline seasonal expectations rather than any specific forecast anomaly for that date.

European weather forecasting agencies including AEMET (Spain's national meteorological service) will issue extended outlooks as July 2026 approaches, though ten-month forecasts carry substantial uncertainty. Near-term catalysts include Atlantic pressure patterns and North African heat dome positioning, typically monitored through June and early July. Traders should track any significant revision in seasonal temperature anomaly predictions during spring 2026, as these would signal material shifts in tail-risk pricing. The settlement window closes at midday UTC, requiring final measurements from the airport station by that timestamp.

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

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 Kalshi vs Polymarket. 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.

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 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.