Highest temperature in Toronto on July 5?

Platform comparison

Market context

A dangerous heatwave is currently intensifying across the East Coast, with New York City reaching 40°C on July 5 and overnight lows staying above 29°C, creating a regional thermal dome that is now pushing north toward Toronto. While the crowd-implied probability for the 27°C outcome in Toronto remains at 0%, this sudden shift in the last 24 hours suggests the market may be underestimating the momentum of this expanding heat event. The real-world driver is the persistent high-pressure system trapping moisture and heat, which has already grounded flights across Canada due to extreme temperatures, indicating the severity of the current atmospheric conditions.

Historically, Toronto Pearson averages a July high of 27°C, with daily highs rarely exceeding 32°C, yet the current East Coast anomaly has already pushed nearby cities well beyond seasonal norms. The 27°C threshold trades at $0.35 YES, but the recent record-breaking midnight temperature of 34.4°C at LaGuardia Airport demonstrates that the heat dome is capable of sustaining extreme values even after sunset, a factor that could elevate Toronto’s peak temperature significantly above the historical mean. Traders should watch the National Weather Service updates for the Toronto Pearson station, specifically the timing of the heatwave’s northern progression and any announcements regarding humidity spikes that could amplify the heat index. The persistence of this system, expected to continue for another day or two before a slight drop by July 7, means the window for a record high in Toronto is still open.

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Methodology

We track Highest temperature in Toronto on July 5? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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

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'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 Prediction Today 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.