Highest temperature in Amsterdam on August 17?

Platform comparison

Market context

On 17 August 2026, the highest temperature recorded at Amsterdam Airport Schiphol Station will determine this market's settlement. The contract currently prices at 0% across all temperature bands, reflecting either extreme illiquidity or a technical artefact in the order book. Traders are pricing conditional tokens on USDC via Polygon, with resolution tied specifically to Weather Underground's Daily Observations table rather than the Day High & Low summary—a distinction that matters when automated systems report conflicting figures.

Amsterdam's August temperatures historically cluster between 20–24°C for daily highs, with extremes reaching 30°C during heat waves. The city recorded 30.0°C on 17 August 2003 during Europe's exceptional summer, and 25.1°C on 17 August 2023. The 0% probability across all bands suggests the market may not yet be actively traded; once liquidity arrives, pricing will reflect seasonal norms and any emerging weather forecasts for that specific date. Traders should monitor whether the contract attracts volume as August 2026 approaches, as even modest trading activity would establish baseline prices against which longer-term weather patterns can be assessed.

The Dutch Royal Meteorological Institute (KNMI) publishes extended forecasts from mid-July onwards, and European weather models typically stabilise their August predictions around six weeks in advance. Any unusual atmospheric patterns—such as persistent high-pressure systems or Atlantic storm tracks—would shift market prices materially. Settlement hinges on Schiphol's official recordings, making data quality and station maintenance relevant considerations for traders evaluating tail-risk scenarios.

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

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.

UK Frequently Asked Questions

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.

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.

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%.