Highest temperature in Amsterdam on July 30?

Platform comparison

Market context

At Amsterdam Airport Schiphol, the key variable is the highest single-day temperature reading, not the overnight minimum or the city-centre feel. In late July, Amsterdam’s climatology is usually mild by European summer standards: average highs are around the low 20s Celsius, while the monthly records show that mid-30s heat is possible but uncommon. That makes the market’s current 0% yes price easiest to read as a statement about the contract terms and settlement mechanics rather than a literal forecast of zero chance; once the final Wunderground observation is posted, the USDC payout is binary and depends only on which temperature bucket contains the day’s peak reading. [2][5][9]

Historical context also suggests why the distribution is usually tight around the low-to-mid 20s in a normal Amsterdam July. Polymarket’s own contract ladder currently clusters the crowd around 25°C and 26°C, both at 21%, with adjacent outcomes close behind, which is consistent with a market expecting a warm but not extreme day. Amsterdam’s July highs typically sit near 21–22°C, and comparable climate datasets show daily highs often remaining below 24°C even in summer, so a reading at the upper end of the 20s would already be above the seasonal norm. [1][5][6][9]

For traders, the main catalysts are short-horizon weather model updates, any late-day shift in cloud cover or wind off the North Sea, and the final Wunderground Schiphol print before the settlement window closes. On-chain, the relevant mechanism is simple: positions settle into USDC once the resolution source is fixed, so liquidity often compresses as the terminal forecast becomes clearer. Broader crypto conditions can still matter at the margin through risk appetite and collateral flows, but for this contract the decisive inputs are the local temperature forecast, the airport station’s official observation, and whether the day’s high is revised at the source before resolution.

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 volatile are crypto prediction markets?

Crypto markets react to spot prices — a 5% BTC move typically shifts a "BTC above X by date" market 10-20%. Polymarket crypto market liquidity is usually six-figure USD, sufficient for active trading.

Are crypto prediction markets taxable in the US?

In the US, prediction market gains are typically treated as ordinary income or short-term capital gains depending on holding period. Consult a tax professional for your specific situation — we cannot provide tax advice.