Highest temperature in Amsterdam on July 30?

Platform comparison

Market context

Polymarket is currently pricing this Schiphol maximum-temperature contract as a low-variance summer weather bet, with the crowd split around the mid-20s Celsius rather than extreme heat. The live book shows **25°C** and **26°C** as the leading outcomes at **21%** each, while the market’s own odds also imply that the temperature range is expected to land somewhere near that band rather than at the tails. Because shares settle to **$1 in USDC on Polygon** if the correct conditional token wins, even a small late move in the forecast can reprice the contract quickly.

That reading fits the broader July climate in Amsterdam, where typical highs are usually in the low 20s Celsius and the month’s historical averages are well below heatwave territory. Long-run summaries for Amsterdam place the average July high around **21°C** and show that temperatures in the low-to-mid 20s are normal, while far hotter outcomes are uncommon but not impossible in the Netherlands. Recent Dutch heat records also matter for calibration: KNMI data reported **33.2°C** in De Bilt on 1 July 2025, underscoring that brief spikes can reach the low 30s even if they are not the base case for Schiphol.

For traders, the main catalysts are the short-range forecast updates from the Met Office, KNMI, and weather services that feed expectations for the afternoon peak, especially any shifts in cloud cover, wind direction, or continental heat advection. The settlement source is Wunderground’s Schiphol station history, so the relevant question is not the city average but the **highest recorded temperature at Amsterdam Airport Schiphol Station** before the 12:00 UTC close of the window. If late-day warming is capped by sea-breeze effects or convective cloud, the market can stay pinned in the mid-20s; if models trend hotter, the upper bins become the only realistic repricing channel.

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Methodology

This page reviews Highest temperature in Amsterdam on July 30? 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 PolyGram, 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.

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.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.