Highest temperature in Toronto on July 5?

Platform comparison

Market context

The highest temperature recorded at Toronto Pearson International Airport on 5 July 2026 is the real-world event this market resolves, with current on-chain pricing assigning a 100% probability to the 26°C outcome and a 0% chance for 21°C or below[1]. This stark consensus contrasts with the adjacent 4 July contract, where long-range guidance pointed to early-July heat clusters of 27–29°C, yet the market settled on 27°C or below[2]. Historical averages for July at Pearson show daily highs around 79°F (26°C), rarely dropping below 70°F (21°C) or exceeding 89°F (32°C), with the peak average high occurring on 20 July at 80°F[5]. The current 0% YES probability for lower ranges aligns with these norms, suggesting the market views a cooler day as statistically improbable given the seasonal baseline.

Traders should monitor the National Weather Service timeseries for CYYZ, which recorded 29.3°C on 3 July, indicating a sustained heatwave entering the settlement window[4]. A key catalyst is the persistence of this heatwave across the Greater Toronto Area, as evidenced by LaGuardia Airport hitting a record midnight temperature of 34.4°C during the same period, confirming regional thermal intensity[10]. While no specific forecast announcements are pending, the dependency on Wunderground’s final daily maximum for CYYZ means traders must watch for any sudden cloud cover or precipitation shifts that could depress the peak temperature below the 26°C frontrunner[1]. The on-chain mechanics, settled in USDC on Polygon via conditional tokens, will reflect these real-time atmospheric dependencies once the settlement window closes on 5 July 2026 at 12:00 UTC.

Sources: 1 · 2 · 3 · 4 · 5

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 Kalshi UK. 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 Kalshi 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.