Highest temperature in Madrid on July 25?

Platform comparison

Market context

The market is pricing a 3% probability that Madrid's highest temperature on 25 July 2026 will exceed 40°C, as measured at Adolfo Suárez Madrid-Barajas Airport. This represents the tail end of the temperature distribution for a summer day in Spain's capital, where heat waves are routine but extreme peaks remain statistically uncommon on any given date. Traders holding YES tokens on Polygon are betting against the baseline expectation for mid-to-late July conditions in the region.

Madrid's July climate provides the historical anchor for calibrating this contract. The city's average high in July sits around 32–33°C, with temperatures regularly reaching 35–38°C during typical heat episodes. Readings above 40°C do occur—the airport station has recorded such extremes in July during particularly intense heat waves—but they represent roughly 5–10% of July days across a multi-decade sample, depending on the specific decade and climate trends. The 3% implied probability reflects a below-historical-baseline assessment, suggesting the market expects either a cooler-than-average pattern or is pricing in recent climate volatility conservatively.

The settlement window closes at midday UTC on 25 July 2026, creating a hard deadline for Wunderground's historical record to populate. Traders should monitor European weather forecasting from mid-July onwards; Spain's meteorological agency (AEMET) and major European models typically signal heat wave timing 10–14 days in advance. Any announcement of a significant high-pressure system stalling over the Iberian Peninsula in late July would shift the probability materially. The contract resolves to the single highest temperature recorded across all hours on that calendar day, making even brief afternoon spikes decisive.

Methodology

This page reviews Highest temperature in Madrid on July 25? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Kalshi UK, which mirrors the Polymarket order book at 0% fees.

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.

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.