Highest temperature in Madrid on July 21?

Platform comparison

Market context

On 21 July 2026, Madrid's highest temperature will be recorded at Adolfo Suárez Madrid-Barajas Airport Station and measured in Celsius. The Polymarket contract currently prices at 0% across all temperature bands, reflecting either extreme uncertainty about which range will resolve or minimal trading activity on this particular weather outcome. Settlement depends on Wunderground's historical weather data for that specific station and date, with the settlement window closing at midday UTC.

Madrid's July temperatures have historically clustered between 32°C and 38°C, with occasional peaks above 40°C during heat waves. The city experienced 40.5°C on 12 July 2022 and 41.4°C on 13 July 2023, establishing that extreme readings are plausible though not routine. July 2019 saw a maximum of 36.4°C on the 21st specifically, providing a direct comparable for the settlement date. These historical ranges suggest the market's current pricing may reflect genuine ambiguity rather than consensus expectation, since any reasonable forecast would assign non-zero probability to at least the 30–35°C and 35–40°C bands.

Traders monitoring this contract should track European weather forecasts from mid-July 2026 onwards, particularly whether an Iberian heat dome develops. Spain's national meteorological agency (AEMET) typically issues extended outlooks 10–14 days in advance. Airport station data can differ slightly from city-centre readings due to elevation and surface characteristics, so historical comparisons should prioritise Barajas-specific records rather than Madrid city averages. The settlement mechanism on Polygon relies on manual verification against Wunderground's archive, introducing a small operational dependency on that platform's data availability.

Methodology

This page reviews Highest temperature in Madrid on July 21? 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.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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.

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.

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.