Highest temperature in Madrid on June 29?

Platform comparison

Market context

The real-world event centres on the highest temperature recorded at Adolfo Suárez Madrid-Barajas Airport on 29 June 2026, with current crowd-implied probability sitting at 0% for a YES outcome. Long-term averages suggest daytime maximums in Madrid during June typically reach 28°C, with low heat and humidity, though recent extremes have pushed significantly higher [1]. Historical records show the warmest day in June is usually 30 June, averaging 31.8°C, while the highest recorded temperature in Madrid for June was 40.7°C on 28 June 2019 [5][9]. This context explains why the market currently prices the event as highly improbable, given that 29 June is not traditionally the peak day and the threshold likely exceeds recent averages.

A power-user evaluating this market programmatically would monitor real-time Wunderground feeds for the airport station, cross-referencing with live heatwave announcements from Euronews, which recently reported Spain breaking two June temperature records with averages of 28.08°C and 28.17°C [3]. Key catalysts include scheduled weather bulletins from the Spanish Meteorological Agency (AEMET) and any sudden shifts in atmospheric pressure that could trigger rapid temperature spikes. Traders should also track dependencies such as cloud cover forecasts and wind direction, as these directly influence peak temperatures. The recent heatwave news underscores that while averages remain moderate, extreme outliers are possible, making automated conditional orders essential for capturing volatility [3].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Madrid on June 29? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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 Polymarket App UK. 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.

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.

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.