Highest temperature in Madrid on June 29?

Platform comparison

Market context

The underlying real-world event is the highest temperature recorded at Adolfo Suárez Madrid-Barajas Airport on 29 June 2026, measured in degrees Celsius. Polymarket prices this contract today with a near-zero probability of the “YES” outcome, implying the crowd expects the temperature to fall below the specified threshold. This pricing reflects on-chain mechanics where USDC trades on Polygon using conditional tokens, locking in expectations before the settlement window closes at 12:00 UTC on 29 June 2026.

Historical data frames this probability sharply: June 2026 in Madrid has seen daily highs between 31.8°C and 38.3°C, with the peak of 38.3°C recorded on 22 June [7]. The warmest average day in June is typically 30 June at 31.8°C [6], yet extreme heatwaves have pushed temperatures to 40.7°C on 28 June 2019 [9]. Given that recent weeks included record heat exceeding 110°F (43°C) in parts of Spain, with 212 excess deaths projected in Madrid [4], the current 0% YES price appears to ignore the potential for another spike on 29 June.

Traders should monitor the daily Wunderground report for Barajas Airport, which settles the market, and watch for any late-announced heat advisories from Spain’s national meteorological agency (AEMET). AEMET issued a red alert for extreme heat across central Spain on 25 June, warning of temperatures over 40°C in Madrid [4]. With no cloud cover forecast and high-pressure systems dominating the region, the catalyst for a temperature surge remains the persistence of this heat dome. The market’s current pricing may shift if Wunderground updates show a rise above the threshold before 12:00 UTC.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to PolyGram, which mirrors the Polymarket order book directly.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

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.

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.