Highest temperature in Madrid on August 7?

Platform comparison

Market context

Polymarket is pricing this Madrid airport temperature contract at **0% YES**, so the market is effectively saying the highest reading in Weather Underground’s Daily Observations table for Adolfo Suárez Madrid-Barajas on 7 August will land outside the listed YES range. Because settlement depends on the *observed* station maximum in Celsius, not the headline “Day High & Low” summary, traders are tied to the airport’s actual intraday peak and its exact bucket on the conditions ladder. The contract itself settles in USDC on Polygon via conditional tokens, so the only thing that matters now is the final Wunderground daily-observation maximum for the station.

The historical read-through is straightforward: Madrid in August is usually hot, and recent forecasts for today pointed to highs around 36°C to 37°C, with some outlets putting the ceiling near 37.9°C or warning of 37°C as a maximum in the metropolitan area.[2][4][5][7][8] That sits close to the lower part of the market’s range, which helps explain why the crowd has not assigned meaningful weight to higher buckets. Reuters also reported Madrid touching 40°C during the first official heatwave of 2026, a reminder that the city can overshoot forecast maxima when synoptic heat builds.[15] For a Polymarket user, that means the relevant comparison is not the citywide forecast but whether the airport station’s recorded peak prints above expectations.

The main catalyst to watch is the late-day Wunderground daily obs update at the airport station, since that is the resolution source named in the market rules.[3] Any afternoon heat warning or forecast revision is only useful insofar as it changes the station’s eventual maximum; AccuWeather had already flagged a yellow extreme-high-temperature warning for Madrid from 13:00 to 21:00 on 7 August, with a maximum temperature of 37°C.[4] In practice, traders are waiting for the final station print rather than the broad city forecast, because a small difference of one degree can move the result between adjacent temperature ranges.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Madrid on August 7? 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 Polymarket Alternative UK, which mirrors the Polymarket order book at 0% fees.

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.

UK Frequently Asked Questions

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 Polymarket Alternative 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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.