Highest temperature in Madrid on May 22?

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Market context

Madrid is set to clear the settlement threshold by a wide margin in almost any normal May pattern. Long-run climate averages for the city point to daytime highs around 21–22C, with May typically sitting in a mild spring range rather than anything close to summer heat. Even the hotter recent-season forecasts in the search results are well below 30C, while the city’s all-time extreme of 40.7C was recorded in July, underlining how unusual true heat is in late May.

That makes the current 0% YES price consistent with the historical distribution: the market is not asking whether Madrid can be warm, but whether it can print a genuinely high late-May maximum at Barajas Airport. Comparable May weather data suggest daily highs usually rise only into the low-to-mid 20sC, and AccuWeather’s monthly outlook for Madrid shows a much cooler band than any threshold typically implied by “highest temperature” markets. In other words, the event would need an unseasonably hot afternoon, not just a pleasant spring day.

The main catalyst is the final Wunderground observation for Adolfo Suárez Madrid-Barajas Airport before the 12:00 UTC settlement window closes. Traders should watch for any rapid warming trend, but also for cloud cover, wind shifts and overnight cool-downs that can cap the day’s maximum well before midday. With only one reading that matters for settlement, the key dependency is whether the airport station records an outlier warmth spike early enough to be captured in the final daily high.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote (Polymarket), four reference venues with their key attributes, and a single execution path — every trade button routes to PolyGram, which mirrors the Polymarket order book directly.

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?

On PolyGram, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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 it cost to trade on PolyGram?

Zero. PolyGram routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, PolyGram triggers a quick verification flow that finishes in minutes.

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.