Highest temperature in Madrid on August 2?

Platform comparison

Market context

Polymarket currently has this contract essentially pinned to **0% YES**, which is notable given that the settlement uses the highest reading from the Adolfo Suárez Madrid-Barajas Airport station on 2 August, with winners paid in USDC via Polygon conditional tokens. For a trader, that means the market is treating the outcome as already effectively decided, so the relevant question is not whether Madrid was hot in the abstract, but whether the airport’s recorded maximum lands in the exact band tied to the contract resolution source on Wunderground.[5]

The comparison set matters because published forecasts for Madrid on 2 August clustered around the mid-30s Celsius, with several sources pointing to around **35–36°C** and some market commentary concentrating on **36°C** and **37°C** as the main outcomes.[1][3][4][5] That is consistent with Madrid’s late-summer climate, where August daytime maxima commonly sit in the low-to-mid 30s, but the airport station can differ from central Madrid and from citywide forecasts, so traders have to focus on the specific observing site rather than headline city weather.[2][7][9][15]

For catalysts, the key watchpoint is the final airport observation and any later corrections on Wunderground, because Polymarket states that revisions within the market window count until the first datapoint for the following date is published.[5] The practical implication is that a late-updated station reading, a delayed archive entry, or a correction to the airport’s maximum can still affect settlement even after the day itself has passed, while broader AEMET-style forecasts mainly matter only insofar as they shaped the pre-close pricing.[1][5]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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 PolyGram. 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.

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.

Do I need to KYC for this market?

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

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.