Highest temperature in Milan on July 21?

Platform comparison

Market context

The highest temperature recorded at Milan's Malpensa International Airport on 21 July 2026 will determine which temperature band resolves this market. Settlement relies on historical data from Weather Underground, with measurement taken across the full calendar day. The 0% crowd-implied probability suggests traders currently view all available temperature ranges as implausible, a positioning that warrants scrutiny given Milan's established summer climate patterns.

Milan's July temperatures have historically clustered between 28–32°C as daily highs, with extreme readings occasionally exceeding 35°C during heat waves. The city recorded 37.0°C on 11 August 2003 and 36.4°C on 15 August 2022, establishing that temperatures in the upper-30s are meteorologically feasible during summer months. The current zero probability across all ranges suggests either a technical issue with market initialisation or extreme risk aversion; comparable weather markets on Kalshi and Polymarket typically show distributed probabilities across multiple temperature bands rather than complete consensus rejection.

Traders should monitor European weather forecasting updates from mid-July 2026, particularly from ECMWF and Météo-France, which provide ten-day outlooks for the Alpine region. Anomalous heat patterns affecting southern Europe in late July could shift probabilities materially. The settlement window closes at midday UTC on 21 July, creating a hard deadline for final data collection from Malpensa's official station records. Any divergence between this market's pricing and comparable temperature contracts on other platforms would indicate potential arbitrage opportunity, though the current uniform zero-probability stance across all ranges suggests limited cross-platform comparison data is available.

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's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

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 Kalshi vs Polymarket trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.