Highest temperature in Madrid on July 21?

Platform comparison

Market context

Madrid's highest daily temperature on 21 July 2026 will be measured at Adolfo Suárez Madrid-Barajas Airport and recorded via Weather Underground's historical database. The settlement hinges on a single data point: the peak temperature reading across all hours on that specific date, converted to Celsius and matched against predefined ranges. This creates a straightforward but data-dependent resolution mechanism, with no ambiguity around location or measurement standard.

Historical July temperatures in Madrid cluster predictably. The city's July average high sits around 32–33°C, with extremes typically ranging from 28°C to 38°C depending on atmospheric patterns. The 0% crowd probability suggests either extreme confidence in a specific temperature band or insufficient liquidity across all ranges. Comparable European airport stations show similar seasonal consistency; Madrid-Barajas data from July 2023 and 2024 provides direct precedent for expected variance. Traders should cross-reference Copernicus Climate Data Store records for July anomalies in the Iberian Peninsula over the past decade to calibrate tail-risk positioning.

The key catalyst is European weather forecasting cycles, particularly ECMWF and GFS model runs issued in early July 2026. Heat dome formation over the Mediterranean—monitored via Meteo-France and AEMET (Spain's national meteorological agency)—can shift expected highs by 3–5°C. Programmatically, traders can automate Weather Underground scraping post-settlement to verify resolution data, though the API's historical endpoint requires manual date queries. Conditional orders tied to ECMWF ensemble forecasts issued 10–14 days prior would capture meaningful signal before market repricing.

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 Polymarket Review UK, which mirrors the Polymarket order book directly.

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

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.

Do I need to KYC for this market?

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

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.