Highest temperature in Madrid on August 7?

Platform comparison

Market context

Madrid’s reading will be set by the highest temperature logged at Adolfo Suárez Madrid-Barajas Airport on 7 August, and the live setup already points to a hot afternoon. AEMET’s Madrid-area warning published this morning put the metropolitan zone on a yellow alert for **37°C**, with the warning window running from 13:00 to 20:59, while other Spanish outlets relayed similar maxima in the **36–37°C** range for the capital.[1][3][11]

That makes the current **0% YES** crowd price look detached from the weather setup rather than from an unusual historical baseline. Mid-August in Madrid commonly sits in the low 30s, but airport peaks above 35°C are not exceptional in heatwave periods, and Reuters reported Madrid reaching **40°C** during Spain’s first official heatwave earlier in 2026, showing that much higher outcomes can occur when the synoptic pattern is entrenched.[12][15] For this contract, the relevant question is not city-average comfort but whether the airport station’s daily maximum falls into the settlement band before the window closes.

Traders should watch the late-afternoon evolution of the thermal peak, because the settlement source is the Weather Underground daily observations table rather than any summary display, and the market can remain open to a higher reading if the maximum is updated before the cutoff. The key dependencies are AEMET’s warning posture, the actual timing of maximum insolation and any dry, downslope flow, plus the liquidity mechanics of the USDC-settled contract itself; in crypto terms, broad risk appetite around BTC and ETH is usually secondary here, but large position flow can still move a thin order book if the temperature band looks close.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

UK Frequently Asked Questions

What does a transaction cost on Polygon?

Polygon gas is typically under $0.01 per transaction. A full trade cycle (Approve + Order + Fill) totals around $0.03 — compared to $5-50 on Ethereum mainnet.

Can I use Bitcoin directly?

No, Polymarket operates exclusively in USDC on Polygon. You can bridge BTC to USDC via an exchange or bridge service and deposit on Polygon — typically 10-30 minutes processing time.

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%.