Highest temperature in Madrid on July 31?

Platform comparison

Market context

Polymarket is pricing this Madrid airport temperature contract at **0% YES** on a **USDC** market settled through **conditional tokens** on **Polygon**, so the book is currently treating a qualifying high as effectively absent. The real-world event is straightforward: the highest temperature recorded at Adolfo Suárez Madrid-Barajas Airport on 31 July 2026, using Wunderground’s daily history page as the settlement source, with the result mapped to the market’s temperature band at the official cut-off.

For context, late-July Madrid regularly prints very warm afternoons, but the airport station still needs to land in the exact settlement range for this market. Wunderground’s historical daily data for Madrid-Barajas shows that the station can post the high-30s Celsius in midsummer, while broader Madrid climate data points to July maxima that often sit around the low-to-mid 30s and occasionally push into the upper 30s or above 40°C in extreme episodes.[12][7][16] That combination means a 0% price only makes sense if traders are either assuming the band is very high, or discounting the odds that the airport observation reaches it before the settlement window closes.

A trader should watch the day’s forecast and any late-morning heat evolution at the airport, because the market resolves on the observed maximum rather than a city-wide forecast. Current reporting for Madrid on 31 July points to a very hot day, with one forecast placing the city maximum at 38°C and no rain, which supports the idea of a strong daytime climb before the 12:00 UTC settlement window ends.[4] The main dependency is the airport station reading itself: if temperatures surge quickly after the morning update, the conditional token payoff can change sharply even when the broader market has already anchored at zero.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to PolyGram, which mirrors the Polymarket order book directly.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.