Highest temperature in Toronto on August 7?

Platform comparison

Market context

Toronto’s reading for 7 August will be set by the highest Celsius temperature logged at Pearson Airport on Weather Underground’s **Daily Observations** table, so the operational question is the intraday maximum rather than the summary high. For a programmatic workflow, that means polling the station page, extracting the day’s observation rows, and locking the final value to the table entry with the highest temperature before the 12:00 UTC settlement cut-off. The broad August backdrop is warm but not extreme: long-range sources put Toronto’s August daytime highs around the mid-20s Celsius, with some forecasts for early August including values near 26–28°C and occasional shower risk.[1][3][13][18]

The current **0% YES** price sits well below what a Toronto summer day can still deliver, but it also reflects that this market settles on a single station-specific daily maximum rather than the citywide forecast headline. Toronto weather in early August often clusters around the seasonal average, yet the historical framing is useful because the observed peak can be pushed up by short-lived afternoon sun, humidity, or pre-frontal warmth even when the day begins cloudy. Recent local reporting described cloud, a chance of showers, and humidex risk across the GTA on 7 August, which is the sort of setup that can either cap the high or leave room for a brief spike if breaks in cloud arrive at the right time.[4][15]

A trader watching this programmatically would want the timing of forecast updates, hourly temperature feeds, and any late-day convection signals, because those drive the last few degrees more than the early-morning outlook. In practice, the main dependencies are the station’s observation cadence, the evolution of cloud cover and precipitation chances, and whether the airport records its warmest reading before or after any afternoon shower band crosses the region.[2][9][12]

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.

UK Frequently Asked Questions

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 Polymarket Review UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.