Highest temperature in Madrid on July 3?

Platform comparison

Market context

Madrid is facing an intense heatwave from 2 to 5 July 2026, with daytime temperatures forecast to soar to 42°C or higher, far exceeding typical July highs for the city. This extreme event directly frames the current 0% crowd-implied probability for the "Highest temperature in Madrid on July 3" market, as the settlement window covers the very peak of this heat spike. Historical data shows 30 July is usually Madrid’s warmest day at 34.1°C, but this year’s anomaly dwarfs that baseline, making a sub-40°C outcome on 3 July statistically implausible under current forecasts.

Traders should monitor real-time updates from Wunderground for the Adolfo Suárez Madrid-Barajas Airport Station, the official resolution source, alongside live weather bulletins warning of peak afternoon heat between 12:00 and 18:00. Recent reporting from Reuters confirms Spain has already entered its first official heatwave of 2026, with temperatures hitting 40°C in Madrid on 21 June, and the national weather agency declaring the first half of 2026 Spain’s hottest ever recorded, with temperatures 1.6°C above normal. Given these dependencies, the conditional tokens on Polygon, settled in USDC, reflect a near-certain resolution above the 40°C threshold, rendering the YES position effectively worthless. The on-chain mechanics lock in this outcome as the settlement window closes at 12:00 UTC on 3 July 2026, leaving no room for doubt amid the recorded extremes.

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Methodology

We track Highest temperature in Madrid on July 3? 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

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.

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 Scam?. 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.

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.

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 Polymarket Scam? trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.