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, based on current USDC liquidity on Polygon. This represents a relatively tight band at the upper extreme of summer heat for the Spanish capital, where the settlement hinges on a single daily maximum reading from Adolfo Suárez Madrid-Barajas Airport Station as recorded on Wunderground.

Historical context suggests the current odds reflect genuine rarity rather than implausible extremes. Madrid has recorded temperatures above 40°C on multiple occasions in recent decades—most notably 40.5°C in August 2018 and 40.7°C in July 2022—but such peaks remain concentrated in late July and August rather than distributed evenly across the summer. The 3% probability aligns with the tail-end distribution of July maxima; whilst July regularly produces days in the mid-to-high 30s Celsius, crossing into the low 40s occurs perhaps once every few years rather than annually. Conditional token mechanics on Polygon mean traders are essentially pricing the intersection of two variables: an unusually intense heat event and its occurrence on this specific date.

Traders monitoring this contract should track European weather pattern forecasts from June 2026 onwards, particularly the position of high-pressure systems over the Iberian Peninsula and any heat dome formation in the weeks preceding settlement. The Spanish meteorological agency (AEMET) typically issues extended outlooks by early July. Proximity to the Mediterranean and local urban heat island effects at the airport station itself remain secondary factors; the primary driver remains synoptic-scale atmospheric conditions that would need to sustain extreme continental heat into late July.

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 PolyGram, which mirrors the Polymarket order book at 0% fees.

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 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.