Highest temperature in Madrid on July 31?

Platform comparison

Market context

Madrid’s airport heat reading for 31 July is trading as a near-dead cert at **0% YES**, which leaves the contract priced as a strong favourite for a sub-threshold outcome rather than a real call on a specific band. Forelytic’s snapshot still points to **37°C** as the modal outcome at **66.5%**, with **38°C** on **30%** and only **5%** combined on **36°C/39°C**.[1] That makes the consensus firmly around the upper-30s, so the main value question is whether the market has overcorrected away from a routine Madrid summer peak and left a small contrarian case for **38°C** or above.[1][8][18]

The historical frame is straightforward: Madrid in July is usually hot, dry and highly solar, with average highs in the low-to-mid 30s, while recent heatwaves have pushed Spanish temperatures into record territory.[8][18][19] AccuWeather’s monthly pages show 31 July sitting in classic midsummer territory, with forecast highs around the mid-30s Fahrenheit-to-Celsius conversion range that still maps to a potentially dangerous afternoon peak if clearing and inland heating line up.[2][4] For a handicapper, the favourite is the 37°C band, but the underdog case is that airport conditions can run a degree or two cooler than the city core, keeping the day just below the consensus top end.

The key catalysts are the daytime forecast updates and, above all, the actual late-afternoon maximum at Madrid-Barajas before the settlement cut-off at 12:00 UTC. Infobae reported a **38°C** high for Madrid on 31 July with **0%** rain, which supports a hot-day bias but also implies that the market’s main debate is not rain risk, but where the peak lands within the upper-30s.[5] Traders should watch whether official and commercial forecasts converge on sustained clear skies and strong insolation, because that is what would justify the higher bands; if cloud cover, earlier convective development or a sea-breeze-like moderation appears, the value shifts back towards **37°C** rather than the top end.[5][9]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Madrid on July 31? 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 Who Will Win 2026, which mirrors the Polymarket order book at 0% fees.

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 Who Will Win 2026. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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'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 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.