Highest temperature in Amsterdam on July 21?

Platform comparison

Market context

The underlying event is the highest temperature recorded at Amsterdam Airport Schiphol on 21 July 2026, measured in Celsius and settled from Wunderground’s daily history page for the station. In practice, this is a single-day airport observation, so the market will move with the actual peak reading rather than with broader Dutch weather averages.

A 0% YES price is consistent with the fact that, as of now, the day has already passed and the settlement source should be available, so the market is no longer trading on forecast uncertainty but on the recorded maximum. For context, Schiphol can see sharp summer volatility: in July 2023 the airport was instead hit by extreme storm conditions, with flights cancelled and the Netherlands affected by strong winds, showing how quickly the same site can swing between heat-driven and storm-driven outcomes.[1]

For traders, the main catalyst is not a campaign-style event but the final Wunderground observation for Schiphol on the settlement day, including whether a late-afternoon or early-evening reading became the day’s maximum. The market’s outcome therefore depends on the station’s logged hourly history, not on national forecasts or nearby locations, so the decisive move comes from the airport record itself once the daily file is complete.

Sources: 1

Methodology

Political prediction markets differ structurally from sports betting: thinner liquidity, longer settlement windows, higher sensitivity to single news events. This page shows the live Polymarket quote for Highest temperature in Amsterdam on July 21? plus platform attributes for the three reference venues, so you can see at a glance where the deepest market for this question sits.

Resolution & payout

Political markets typically settle on official candidate or agency confirmation. Polymarket uses UMA Optimistic Oracle: a proposer posts the outcome with a bond, the two-hour window opens, then the smart contract pays USDC.

Kalshi settles USD via CFTC clearinghouse, with clearly defined resolution sources (e.g. AP race calls for elections). Betfair settles after the official outcome is registered with the league or agency. Manifold is play-money.

FAQ

How accurate are political prediction markets?

Historically more accurate than polls. Polymarket's Brier score on US 2024 elections was ~0.11 — better than 538 (~0.14) and every mainstream poll. Markets aggregate information with real skin in the game.

What resolution source is used for elections?

Polymarket defines the source per contract — usually Associated Press (AP Race Call), Reuters or the official electoral commission. The source is stated in contract details before the market opens.

How fast do political markets react to news?

High-liquidity markets move within seconds to minutes. A Trump tweet on the economy can shift the "Trump 2024" market 2-5 points before mainstream media has written anything.

Why do Polymarket and Kalshi differ on elections?

Kalshi must follow CFTC compliance — strict definitions, clear resolution sources, US citizens only with KYC. Polymarket operates globally without CFTC oversight — deeper liquidity, but also higher regulatory risk.

Which political events have the biggest volume?

US Presidential election, party nominations (DNC/RNC), Senate majorities, individual state outcomes (Pennsylvania, Michigan, Wisconsin), and major European elections. Peak markets reach $50-500M per event.