Highest temperature in Madrid on June 28?

Platform comparison

Market context

The real-world event driving this market is the peak daytime temperature recorded at Madrid-Barajas Airport on 28 June 2026, a date historically prone to significant heat spikes. Long-term averages suggest a typical June maximum of 28°C, yet the current 0% YES probability implies the crowd expects temperatures to remain well below the upper resolution thresholds, despite the region’s recent volatility.

Historical data frames this expectation sharply: on 28 June 2019, Madrid hit 40.7°C, the highest June temperature recorded in the city since 1920[5]. This extreme outlier contrasts with the 28°C average, suggesting that while cool days are common, the potential for a 40°C+ spike remains non-trivial. The crowd’s dismissal of high-temperature outcomes may overlook this specific anniversary effect, where similar dates have previously triggered record-breaking heat.

A power-user evaluating this market programmatically should monitor real-time heat alerts from Aemet, Spain’s state meteorological agency, which recently placed 13 regions under orange heat alerts[10]. Traders must watch for sudden shifts in the European heatwave narrative, as Spain has already smashed multiple June records this month, including a 43.7°C peak in Cantabria[3]. Conditional orders should be triggered by any Aemet announcement elevating Madrid’s alert status, as these dependencies directly correlate with temperature spikes that could invalidate the current 0% probability.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Madrid on June 28? 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 Review UK, 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 Polymarket Review 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 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.