Highest temperature in Milan on July 21?

Platform comparison

Market context

The settlement hinges on the single highest temperature recorded at Milan's Malpensa International Airport on 21 July 2026, measured in Celsius and resolved against historical data from Weather Underground. The crowd is currently pricing this outcome at zero probability, suggesting either extreme confidence in a specific temperature range or minimal trading activity to establish a baseline.

Milan's July climate is characterised by warm to hot conditions, with historical highs typically ranging between 28–32°C, though peaks above 33°C occur during heat waves. The 0% implied probability across all ranges signals either that traders have already concentrated positions in a single bracket or that the market lacks sufficient liquidity to reflect genuine uncertainty. Comparable European summer markets show that late-July temperatures in the Po Valley region frequently test the upper 30s, particularly during the anticyclonic patterns common to that season. Without recent trading activity establishing a consensus, the current odds reflect no meaningful price discovery.

Traders should monitor European weather forecasting models as July 2026 approaches, particularly the extended-range outlooks from ECMWF and GFS issued in late June, which typically gain reliability within a fortnight of the settlement date. Heatwave alerts issued by Italy's Protezione Civile or significant atmospheric blocking patterns developing over southern Europe would shift expectations materially. The absence of current probability mass suggests the market may be awaiting either fresh liquidity or clearer seasonal forecasts before meaningful positions form.

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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Who Will Win 2026. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Who Will Win 2026 trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.