Highest temperature in Amsterdam on August 17?

Platform comparison

Market context

On 17 August 2026, the highest temperature recorded at Amsterdam Airport Schiphol will determine which temperature band this market resolves to, with settlement occurring at midday UTC. The resolution methodology specifies the Daily Observations table from Weather Underground as the authoritative source, bypassing any conflicting figures in summary sections—a distinction that matters when automated weather stations and manual observations occasionally diverge.

Amsterdam's August climate sits firmly within predictable bounds. Historical data from the past two decades shows maximum temperatures on mid-August dates clustering between 20°C and 27°C, with extremes rarely exceeding 30°C or falling below 18°C. The 0% crowd probability across prediction markets suggests traders are either awaiting range specification or treating this as a placeholder contract pending clearer outcome definitions. Comparable weather markets on Polymarket and Kalshi typically see meaningful divergence only when temperature thresholds approach historical percentiles—the 90th or 95th percentile boundaries where genuine forecast uncertainty emerges.

The primary catalyst remains the absence of published temperature ranges in the market description. Until specific bands are defined (such as 20–22°C, 23–25°C, 26–28°C), traders cannot calibrate positions against meteorological forecasts or historical distributions. The Royal Netherlands Meteorological Institute (KNMI) publishes seasonal outlooks and monthly climate summaries; any August 2026 advisory suggesting anomalous heat or cold would shift baseline expectations. Standard European summer weather patterns—Atlantic low-pressure systems versus continental high-pressure ridges—will determine whether conditions favour above or below-normal temperatures during that specific date.

Methodology

We track Highest temperature in Amsterdam on August 17? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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

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.

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.

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.