Highest temperature in Amsterdam on August 17?

Platform comparison

Market context

Amsterdam's highest temperature on 17 August 2026 will be measured at Schiphol Airport's official weather station and resolved against the Daily Observations table on Weather Underground, not the summary high-low figures that often appear in casual weather reports. This distinction matters: the Daily Observations table records readings at finer granularity, sometimes capturing peaks that summary sections miss. The settlement window closes at noon UTC on that date, meaning afternoon temperature spikes after the cutoff will not count.

Historical August temperatures in Amsterdam show a median high around 22–23°C, with extremes ranging from 17°C to 32°C across the past two decades. The 0% crowd probability suggests traders are either uncertain about the exact range brackets offered or expect below-median conditions. On Polymarket, this market would display decimal odds; Kalshi's binary format may attract different trader cohorts depending on how the range thresholds are structured. Betfair and Smarkets typically offer tighter spreads on European weather once the event date approaches, though liquidity varies by specificity of the outcome.

Traders should monitor European weather forecasting updates from mid-August onwards, particularly jet stream positioning and high-pressure systems over the continent. The Royal Netherlands Meteorological Institute (KNMI) publishes extended forecasts that often diverge from global models; comparing their 10-day outlook against Wunderground's historical volatility patterns will clarify whether the current probability reflects genuine uncertainty or simply thin early-market liquidity. Schiphol's elevation and urban heat island effects can push readings 1–2°C higher than surrounding rural areas during clear, calm days.

Methodology

This page compares Highest temperature in Amsterdam on August 17? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Kalshi Alternative, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.

FAQ

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Kalshi Alternative has a different geo footprint and routes to Polymarket's order book at 0% fees.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.