Highest temperature in Madrid on August 9?

Platform comparison

Market context

Madrid’s airport is sitting in a hot, but not exceptional, late-summer regime, and that is why the contract is clustered around the high-30s rather than the low-40s. Official and commercial forecasts for 9 August point to a sunny, very hot day with highs around 36–38°C, while Weather Underground’s Madrid history page shows an August record high at the airport of 42.7°C, confirming that the venue can occasionally spike far above forecast normals.[2][4][11][15]

That context matters because the current 0% YES reading on the market is at odds with both the weather setup and the public forecast stack. Polymarket’s own market page shows 37°C as the clear leader, while nearby forecast products sit mostly in the 36–38°C band, with AccuWeather also posting a yellow warning for extreme high temperature with a 38°C cap in the metropolitan area.[8][9][2][3] By contrast, a sportsbook-style price of 0% implies the wrong contract is being referenced or that liquidity is thin enough to misprice an otherwise straightforward heat event; analysts’ consensus, as reflected in forecast models and the market’s dominant 37°C outcome, is materially higher than zero.[9]

Traders should watch for late afternoon observations at Madrid-Barajas, because the market resolves from Weather Underground’s Daily Observations table rather than the summary high/low box, and revisions remain relevant until the first datapoint for 10 August is published.[9] The main dependency is the day’s actual maximum arriving before the settlement window closes at 12:00 UTC, which means any late-afternoon surge in the airport reading can still move the contract after midday local time. Sunny conditions, light winds and the ongoing heat warning all favour a top reading in the mid-to-high 30s, so the real comparison is between a 37°C print and a small tail risk around 38°C, not between heat and cool weather.[2][3][8]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Madrid on August 9? 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 Kalshi vs Polymarket, 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 Kalshi vs Polymarket. 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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi vs Polymarket trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.