Highest temperature in Madrid on July 21?

Platform comparison

Market context

Madrid is bracing for a severe heatwave in mid-July 2026, with central Spain expected to face daytime highs between 37°C and 41°C. The market currently assigns a 66% probability to the highest temperature at Barajas Airport reaching exactly 37°C, while 38°C holds a 28% chance, suggesting traders anticipate the peak will sit at the lower end of the forecasted range despite extreme regional warnings [1][2].

Historical July data for Madrid typically sees peaks around 35–36°C, but the 2026 event represents a significant outlier, with forecasts pushing southern and central temperatures toward 43–46°C in the coming weeks [2]. The current 0% implied probability for lower ranges reflects confidence that the heatwave will breach standard summer norms, aligning with the 37°C frontrunner as the most likely ceiling for the airport station specifically, even as surrounding areas like Seville may hit 44°C [1][2].

Traders should monitor daily updates from Wunderground for the official Barajas record and watch for shifting cloud cover or storm forecasts that could moderate temperatures by the settlement deadline on 21 July 2026 [2]. While the broader heatwave lingers through the fourth week, the market leans on the specific dependency of whether the airport station records will cap at 37°C before any potential cooling from the occasional storm mentioned in late-week forecasts [2].

Sources: 1 · 2

Methodology

Political prediction markets differ structurally from sports betting: thinner liquidity, longer settlement windows, higher sensitivity to single news events. This page shows the live Polymarket quote for Highest temperature in Madrid on July 21? plus platform attributes for the three reference venues, so you can see at a glance where the deepest market for this question sits.

Resolution & payout

Political markets typically settle on official candidate or agency confirmation. Polymarket uses UMA Optimistic Oracle: a proposer posts the outcome with a bond, the two-hour window opens, then the smart contract pays USDC.

Kalshi settles USD via CFTC clearinghouse, with clearly defined resolution sources (e.g. AP race calls for elections). Betfair settles after the official outcome is registered with the league or agency. Manifold is play-money.

FAQ

Can prediction markets influence election outcomes?

Markets reflect expectations rather than create them. Studies show public-facing markets can anchor expectations, but don't influence the underlying outcome. Political markets are information, not advocacy.

Which platform has the deepest political liquidity?

Polymarket — by far. US 2024 presidential volume was ~$3.5B vs Kalshi (~$200M) and Betfair (~$120M). Where Polymarket is geo-blocked, brokers like Trump Prediction route into the same order book at 0% fees.

Are political prediction markets legal in my country?

It varies. They sit in legal gray areas in most jurisdictions. Polymarket is geo-blocked from US/UK/EU; some broker frontends have a different geo footprint. Trade only with capital you can afford to lose, and only if you understand the legal status in your jurisdiction.

Why do Polymarket and Kalshi differ on elections?

Kalshi must follow CFTC compliance — strict definitions, clear resolution sources, US citizens only with KYC. Polymarket operates globally without CFTC oversight — deeper liquidity, but also higher regulatory risk.

Which political events have the biggest volume?

US Presidential election, party nominations (DNC/RNC), Senate majorities, individual state outcomes (Pennsylvania, Michigan, Wisconsin), and major European elections. Peak markets reach $50-500M per event.