Highest temperature in Milan on July 21?

Platform comparison

Market context

On 21 July 2026, Milan's highest temperature will be recorded at Malpensa International Airport, with settlement determined by historical weather data from Weather Underground. The market currently shows 0% implied probability across all temperature ranges, suggesting either incomplete pricing or a data-loading issue rather than genuine consensus that no temperature will be recorded. Milan's July climate typically produces daily highs between 28–32°C, with occasional peaks above 33°C during heat waves. The 0% reading across all brackets diverges sharply from typical weather-market behaviour, where temperature ranges normally distribute probability mass reflecting seasonal norms and recent atmospheric patterns.

Historical July temperatures at Malpensa show considerable year-to-year variation. The airport recorded 34.8°C on 18 July 2022 and 35.6°C on 19 August 2003, establishing that ranges above 33°C are meteorologically plausible for northern Italy in summer. Comparable European airport stations price similar July heat events with meaningful probability across multiple brackets, typically concentrating mass in the 28–32°C band with tail risk for extremes. The complete absence of probability allocation here suggests a technical discrepancy rather than informed trader consensus.

Traders should monitor European weather forecasting updates from mid-July 2026, particularly anomaly alerts from ECMWF and GFS models. Atmospheric blocking patterns and heat dome formation across the Mediterranean typically become clearer 10–14 days before the settlement date. Any significant divergence between this market's eventual pricing and comparable temperature markets on other European cities would indicate whether the current 0% reading reflects genuine market view or a settlement mechanism requiring correction.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Best Prediction Markets UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.