Highest temperature in Amsterdam on July 21?

Platform comparison

Market context

The contract will settle on the **highest temperature** recorded at Amsterdam Airport Schiphol on 21 July 2026, using Wunderground’s daily history for Schiphol. With the crowd pricing **0% YES**, the market is effectively treating an above-threshold reading as absent or no longer in play, so the key comparison is between that near-zero market view and whatever the official daily maximum ultimately showed in the observation record.

For context, Schiphol’s July temperatures are usually moderated by the North Sea, so extreme daytime highs are less common than in inland Dutch stations, but short-lived warm spells can still push the daily maximum into the upper 20s Celsius. In weather contracts, a 0% implied probability usually signals either a clearly beaten target, a data-quality issue, or a market that has already internalised the likely resolution from the observed daily range; without a sportsbook line or analyst forecast published for this specific station-day combination, the prediction market price is the main live signal.

The trader catalysts are straightforward: the only decisive inputs are the station’s archived maximum temperature and whether Wunderground’s daily page is updated cleanly for the full settlement window. Late adjustments, missing observations, or a discrepancy between Celsius display settings and the market’s range bands can matter more than headlines. If contemporaneous forecasters had been tracking a warm-front setup over the Netherlands, that would have been the main external driver, but in this contract the settlement source itself is the dominant dependency.

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

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 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 fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

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.