Highest temperature in Amsterdam on July 31?

Platform comparison

Market context

The event is the highest temperature recorded at Amsterdam Airport Schiphol on 31 July 2026, with settlement based on the Wunderground daily history entry for that station. As of early afternoon UTC, the market’s 0% crowd-implied YES price suggests traders are treating an extreme reading as very unlikely, which is consistent with Amsterdam’s July climate: average highs are around 22°C, and 31 July typically sits in the low 20s rather than heatwave territory.[6][8][13]

Historically, Amsterdam can spike into the mid-to-high 30s Celsius, but those outcomes are rare and usually tied to broader European heat episodes. The city’s recent records include 35.8°C on 1 July 2025, while Amsterdam’s all-time highs in late July reached 36.4°C in 2019; at the national level, the Netherlands set a record of 40.7°C in 2019, showing that exceptional heat is possible even if it is not the base case.[14][10] In probability terms, a 0% market price usually implies the crowd sees the upper temperature bands as outside the normal distribution for this date rather than impossible.

The main catalysts are the local forecast into the afternoon, any late-day convective warming, and whether sea-breeze or cloud cover suppresses the airport reading relative to central Amsterdam. Current forecasts for Amsterdam show a warm but modest day, with highs around 26°C and only a small drizzle chance, which would normally keep the settlement reading well below the upper extremes unless conditions overperform sharply.[3] Traders also watch the final Wunderground update cadence and, in crypto terms, whether broader risk sentiment in BTC and ETH shifts weekend positioning; that matters less to the weather itself than to how aggressively liquidity and whale flows price tail outcomes on-chain before expiry.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

FAQ

What are crypto prediction markets?

Crypto prediction markets are on-chain smart contracts where you buy YES or NO shares on a future crypto event (e.g. "BTC above $100k by year-end"). The market price between 0¢ and 100¢ is the implied probability.

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

What does a transaction cost on Polygon?

Polygon gas is typically under $0.01 per transaction. A full trade cycle (Approve + Order + Fill) totals around $0.03 — compared to $5-50 on Ethereum mainnet.

How does UMA secure the resolution?

The UMA Optimistic Oracle uses a bond system: a proposer posts a bond, a two-hour challenge window opens. On dispute the losing side forfeits the bond — financial incentive for honest resolution.

Which crypto markets exist on Polymarket?

Currently active markets include BTC/ETH/SOL price targets, halving dates, ETF approvals, hard-fork outcomes and Layer-2 TVL thresholds. The list updates weekly; biggest volume sits on BTC and ETH price forecasts.