Highest temperature in Toronto on May 25?

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Active sub-markets

Market context

On 25 May 2026, Toronto Pearson International Airport's weather station will record a daily high temperature in Celsius. Polymarket currently prices this contract at 0% YES, indicating traders see negligible probability of the temperature landing in the uppermost range. The settlement hinges on Wunderground's historical data feed for that specific date, with resolution finalised by 12:00 UTC the following day. Traders are effectively betting conditional tokens (USDC-backed) on which temperature bracket—likely spanning 5°C increments—will contain the day's peak reading.

Toronto's May climate shows considerable year-to-year variance. Historical records from Environment Canada indicate late-May highs typically range between 18°C and 24°C, though outlier warm days occasionally push toward 28–30°C. The 0% pricing suggests the market has assigned negligible odds to extreme heat on that particular date, possibly reflecting seasonal norms or algorithmic anchoring to recent springs. Comparable May 25th observations from prior years would provide calibration, though single-day weather forecasting remains inherently uncertain beyond a fortnight.

Traders monitoring this contract should track Environment Canada's extended forecast as May 2026 approaches, particularly any signals of early-season heat waves or anomalous pressure systems affecting Ontario. Atmospheric circulation patterns established in early May often persist through month-end. The current pricing leaves room for repricing if seasonal forecasts shift toward warmer conditions, though the settlement window's proximity to the event date means late-stage probability adjustments will compress sharply.

Methodology

This page reviews Highest temperature in Toronto on May 25? across five venues. We show live odds for Polymarket-based markets (sourced from the Polygon order book); for other venues we list platform attributes, since the comparable contracts are not exposed via a public API on every venue. Every CTA points at PolyGram — the application we operate, where you trade directly against the Polymarket order book at 0% fees.

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?

On PolyGram, which mirrors the Polymarket order book at 0% fees. 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 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.

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.