Highest temperature in Toronto on May 25?

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Market context

On 25 May 2026, the highest temperature recorded at Toronto Pearson International Airport will determine the settlement outcome for this market. The resolution mechanism relies on historical weather data logged by Weather Underground, capturing the daily maximum across all hours at the station located in Mississauga, Ontario. Settlement occurs in USDC against the temperature range brackets, with the crowd currently assigning zero probability to any outcome—a signal that traders have not yet priced expectations for this date or that the market lacks sufficient liquidity to establish a consensus range.

Toronto's May temperatures typically range from 15 to 23 degrees Celsius, with historical maxima on 25 May clustering between 20 and 26 degrees across the past two decades. The 0% crowd probability suggests either minimal participation or a technical artefact in early market formation rather than genuine bearish conviction on all temperature brackets. Comparable late-May days in Toronto show considerable variance; the city recorded 28.3°C on 25 May 2018 but only 16.1°C on the same date in 2015, illustrating the seasonal volatility traders must account for.

Weather forecasting accuracy degrades beyond ten days, making near-term catalysts less material than broader seasonal patterns. The settlement window closes at 12:00 UTC on 25 May 2026, giving traders until that point to monitor Environment Canada's official forecasts and any anomalous weather systems developing in the preceding weeks. Traders should watch for late-spring heat domes or cold fronts that could push temperatures toward extreme ranges, though such events remain difficult to predict more than a fortnight in advance.

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 — are listed with their platform attributes, because they operate off-chain and a 1:1 comparison of contract mechanics isn't possible.

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

Is this market available outside the US?

PolyGram is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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 it cost to trade on PolyGram?

Zero. PolyGram routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, PolyGram triggers a quick verification flow that finishes in minutes.