Highest temperature in Toronto on August 2?

Platform comparison

Market context

Toronto Pearson’s hottest reading on 2 August will be set by a single day of airport observations, and the market’s 0% YES price only makes sense if the relevant outcome range is well above what forecasters expect. August normals for Toronto imply daytime highs in the mid-20s Celsius, with the long-run average for 2 August around 26.7°C and a record high for that date of 33.9°C, so most historical summers would land far below an extreme-temperature bucket. Recent daily forecast pages also pointed to a modest summer high rather than a major spike, with one August outlook showing 27°C for 2 August and broader monthly guidance clustering roughly between the high 20s and low 30s Celsius.[10][7][2]

That makes the cross-platform comparison straightforward: the prediction market appears to be pricing the contract as essentially non-travelling, while public weather references still leave a plausible path to a warm but not exceptional result. A recent Toronto heat episode reached 36°C in late July, showing that top-end outcomes are possible in this region, but that sits well above the normal August profile and would require a sustained heat plume to repeat at Pearson.[13][18] For context, comparable late-summer Toronto markets have recently shown very strong crowd conviction on specific temperature bins, with one nearby contract pricing a 30°C outcome at 100%, which underlines how sharply traders distinguish between ordinary warmth and record-chasing heat.[9]

The main catalysts are the latest airport forecast updates, any heat advisories or shifting upper-air patterns, and the exact timing of the Pearson observation window before the settlement cut-off. If model guidance trends cooler overnight or a shower/storm line passes through the GTA, the daily maximum can easily stay pinned in a lower range; if heat builds earlier and lingers, the high could move into the low 30s Celsius without needing a formal record. Traders should therefore watch the midday forecast revisions and the airport’s reported peak temperature, since the contract settles on the highest reading recorded at Toronto Pearson rather than a citywide average or a one-hour snapshot.[2][10]

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

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

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.

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.

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.

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.