Highest temperature in Toronto on July 16?

Platform comparison

Market context

Toronto Pearson International Airport will record its peak daily temperature on 16 July 2026, with the market resolving to the specific Celsius range containing that high. Programmatic traders should treat the current 0% implied probability for the lowest outcome as a data anomaly rather than a consensus view, given that the frontrunner outcome is 30°C at 25% probability, closely trailed by 27°C or below at 24% [1]. This distribution suggests the market expects a warm day, contradicting the zero probability assigned to the cooler bracket.

Historical context from the same date last year reinforces the likelihood of elevated temperatures, as 16 July 2025 triggered an extreme heat warning and public health advisory for the region [2]. During that event, peak heat hours were identified between 11 AM and 4 PM, a window that typically dictates the daily maximum reading at the airport station. A trader building a bot to scrape Wunderground history would note that similar July dates frequently breach the 27°C threshold, making the current 0% probability for the lower range statistically fragile.

The primary catalyst for price discovery is the real-time temperature feed from the Toronto Pearson station, accessible via the Wunderground daily history portal for CYYZ. Traders should monitor the 11 AM to 4 PM window closely, as this period historically produces the daily peak [2]. Since the settlement window closes at 12:00 UTC on 16 July 2026, any automated strategy must ingest the final recorded high before this deadline to avoid latency errors in conditional order execution.

Sources: 1 · 2 · 3

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

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Bot UK 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.