Highest temperature in Madrid on July 3?

Platform comparison

Market context

Madrid is currently locked in an intense heatwave from July 2 to 5, with daytime temperatures forecast to soar to 42°C or higher under stable high pressure and clear skies[2]. This extreme event is far above the city’s typical July highs, which usually range between 90°F and 103°F (32°C to 39°C)[3]. The market on Polymarket prices the “37°C” outcome at 61%, with “36°C” trailing at 19%, reflecting strong on-chain conviction that temperatures will breach the 36°C threshold despite the current crowd-implied 0% probability for a lower range[1].

Historical context frames this probability sharply: Spain recorded its hottest day since 1928 on July 18, 2026, at 45.4°C in Figueres, and the first half of 2026 was the hottest ever for the country, with temperatures 1.6°C above normal[5][7]. The first official heatwave of 2026 struck on June 21, pushing Madrid to 40°C, setting a precedent for sustained extreme heat in early summer[4]. Traders should watch for official meteorological announcements from AEMET and updates on the heatwave’s duration, as the settlement window ends 2026-07-03T12:00:00Z, making real-time Wunderground data critical for resolution[2]. Conditional tokens on Polygon, settled in USDC, will reflect these on-chain price movements as the heatwave intensifies.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, 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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

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.

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.

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.