Highest temperature in Milan on August 17?

Platform comparison

Market context

On 17 August 2026, the highest temperature recorded at Milan's Malpensa International Airport will determine which temperature band this market resolves to, with settlement occurring at midday UTC. The crowd-implied probability of 4% for the YES outcome suggests traders are pricing a notably low likelihood of extreme heat on that specific date, though the exact temperature threshold defining YES remains contingent on the market's range structure.

Milan's August climate typically produces daily highs between 28–32°C, with extreme readings above 35°C occurring in roughly 5–10% of August days across a thirty-year window. The 4% probability currently embedded in this contract sits below historical frequency, indicating either conservative positioning ahead of the 2026 summer season or confidence in near-normal conditions. Recent European summer patterns have shown increased volatility, yet long-range forecasting for a specific date fourteen months ahead carries substantial uncertainty; comparable single-day temperature markets in Mediterranean cities have historically seen probabilities drift significantly as the settlement date approaches.

Traders should monitor European weather pattern forecasts released in late July and early August 2026, particularly Atlantic high-pressure systems and their positioning relative to the Alpine region. The European Centre for Medium-Range Weather Forecasts (ECMWF) and national meteorological services will issue increasingly precise ten-day outlooks in the week preceding 17 August. Any significant heat dome formation across southern Europe in mid-August would likely trigger repricing, as would cooler-than-average jet-stream configurations. The resolution methodology's reliance on Weather Underground's Daily Observations table rather than summary figures means traders should verify data consistency across platforms before settlement.

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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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 PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.