Highest temperature in Madrid on July 31?

Platform comparison

Market context

Madrid’s high temperature on 31 July will be measured at Barajas airport, and the market resolves off the day’s peak reading there rather than the citywide forecast. Early public forecasts point to another very hot afternoon: Infobae reported a maximum of 38°C for Madrid on 31 July, while AccuWeather’s monthly view for Madrid shows a late-July high in the mid-30s to mid-90s Fahrenheit range, consistent with heat carrying through the day.[4][1][6]

The main frame for this market is not a binary heatwave call but how far above seasonal norms Barajas gets. July averages in Madrid are already high, with WeatherSpark describing typical daily highs around 31–33°C and noting that July maxima rarely fall below 26°C or exceed 37°C, which makes anything in the upper 30s a meaningful overshoot.[7][9] That history matters because the crowd-implied 0% YES appears to be leaning on the idea that the airport station will top out well below the hottest city-centre forecasts, but Madrid’s recent summers have repeatedly pushed into the 40°C neighbourhood, so the risk is a late-afternoon spike rather than a mild finish.[16][11]

For traders, the key catalyst is the sequence of same-day updates rather than any scheduled political-style event: revised afternoon forecasts, observed airport temperatures, and whether the heat peaks before the settlement window closes at 12:00 UTC. The market is effectively leaning on the latest weather guidance from local reporting and forecast services; if Barajas warms quickly after midday, the upper buckets become more plausible, but if clouds or an early plateau limit the rise, the lower range will keep control.[4][19][12]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page tracks Highest temperature in Madrid on July 31? across four political prediction venues. Live odds come from the Polymarket order book (the deepest political prediction-market book). Kalshi is the CFTC-regulated US alternative, Betfair the established UK sports-exchange with politics markets, Manifold the open play-money variant. For users geo-blocked from Polymarket directly, brokers like Election Predictions UK provide a 0%-fee route into the same order book.

Resolution & payout

For political markets the resolution source is decisive. Polymarket defines a concrete source per contract (e.g. AP, Reuters, official electoral commission) and uses the UMA Optimistic Oracle as the on-chain dispute mechanism. With a clearly defined outcome the USDC payout lands within minutes of the final confirmation.

FAQ

How accurate are political prediction markets?

Historically more accurate than polls. Polymarket's Brier score on US 2024 elections was ~0.11 — better than 538 (~0.14) and every mainstream poll. Markets aggregate information with real skin in the game.

What resolution source is used for elections?

Polymarket defines the source per contract — usually Associated Press (AP Race Call), Reuters or the official electoral commission. The source is stated in contract details before the market opens.

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 Election Predictions UK route into the same order book at 0% fees.

How fast do political markets react to news?

High-liquidity markets move within seconds to minutes. A Trump tweet on the economy can shift the "Trump 2024" market 2-5 points before mainstream media has written anything.

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.