Highest temperature in Milan on July 21?

Platform comparison

Market context

On 21 July 2026, the highest temperature recorded at Milan's Malpensa International Airport will fall into one of several defined ranges. This market settles based on historical weather data logged by Weather Underground for that specific station and date, with resolution occurring at 12:00 UTC on the settlement day itself. The measurement captures the peak temperature across all hours of that calendar day in degrees Celsius.

Milan's summer climate typically produces highs between 28–32°C in late July, though heat waves can push readings above 35°C. Historical data from Malpensa shows that extreme heat events—temperatures exceeding 36°C—occur roughly once every five to seven years during peak summer months. The current 0% implied probability on higher temperature ranges suggests the market crowd expects a relatively moderate day, consistent with typical late-July conditions rather than an anomalous heat spike. Comparable European weather markets have shown that seasonal norms anchor pricing until specific meteorological warnings emerge.

Traders should monitor European weather forecasting updates from mid-July onwards, particularly alerts from Italy's civil protection agency regarding heat waves or high-pressure systems. The Copernicus Climate Data Store and ECMWF medium-range forecasts become increasingly reliable five to ten days before the settlement date. Any significant deviation from seasonal patterns—such as a Saharan dust event or persistent anticyclonic conditions over southern Europe—would shift probability distributions materially. Settlement depends entirely on the Wunderground historical record for Malpensa, which remains the authoritative source for this contract's resolution.

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 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.

Can I use Bitcoin directly?

No, Polymarket operates exclusively in USDC on Polygon. You can bridge BTC to USDC via an exchange or bridge service and deposit on Polygon — typically 10-30 minutes processing time.

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.

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.