Highest temperature in Amsterdam on August 17?

Platform comparison

Market context

Amsterdam's daily maximum temperature on 17 August 2026 will be recorded at Schiphol Airport, with resolution determined by the granular 'Daily Observations' dataset on Weather Underground rather than the summary 'Day High & Low' figure. This distinction matters for automated resolution: the observations table captures sub-hourly readings and can differ materially from rounded summary statistics, particularly during volatile weather patterns. A trader building conditional logic around this market needs to account for the specific data hierarchy outlined in the settlement criteria.

August in the Netherlands typically sees daily highs between 20–24°C, though heat waves occasionally push readings into the upper twenties. The 0% crowd probability suggests either a narrow range being priced or substantial uncertainty about which temperature bracket will resolve. Historical August data from Schiphol shows extremes ranging from 16°C in cooler years to 30°C during heat events; the 2003 European heat wave and the 2022 summer spike provide reference points for how far temperatures can deviate from seasonal norms. Examining Schiphol's August records from the past decade reveals that temperatures exceeding 28°C occur roughly once every three to four years.

Traders should monitor European weather forecasting updates from mid-August, particularly from KNMI (Royal Netherlands Meteorological Institute) and Meteo Consult, which publish detailed 10-day outlooks. Jet stream positioning and Atlantic pressure systems drive Dutch summer temperatures; any significant blocking high-pressure system or Atlantic storm track shift in early-to-mid August will signal directional bias. Programmatically, integrating KNMI's open data feeds or Weather Underground's API allows continuous monitoring of forecast consensus as the settlement date approaches, enabling dynamic position adjustments based on ensemble model agreement.

Methodology

This page reviews Highest temperature in Amsterdam on August 17? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Polymarket Bot UK, which mirrors the Polymarket order book at 0% fees.

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.

UK Frequently Asked Questions

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 Polymarket Bot UK. 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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.