Highest temperature in Toronto on August 7?

Platform comparison

Market context

Polymarket has this Toronto heat contract at **0% YES** today, which on-chain means the conditional token is priced as near-worthless in USDC terms on Polygon unless a materially hotter reading appears in Weather Underground’s station data. Because settlement is tied to the **Daily Observations** table at Toronto Pearson, not the broader day-high summary, traders are really betting on the exact reported maximum for a single airport station rather than on a generic city forecast.

That is a hard level to anchor against Toronto’s late-summer climatology. Typical August highs in the city sit around the mid-20s Celsius, with forecast services still showing day highs generally in the 25–31°C range across early August and several damp or showery periods rather than sustained extreme heat.[1][3][11][17][19] Recent forecast copy also pointed to “cloudy with a chance of rain” and humid conditions in the GTA, which matters because cloud cover and showers can cap daytime maximums even when the air feels oppressive.[4][15][19]

For traders, the main catalysts are the late-cycle weather updates: any shift in the Toronto Pearson hourly or daily forecast, plus the actual afternoon temperature trajectory on 7 August before the settlement window closes at 12:00 UTC. Weather Underground’s current Toronto page is the relevant live source for checking whether the station is tracking towards an outlier reading, while local forecast updates from AccuWeather and Toronto media provide the broader setup for thunderstorms, humidity and sunshine breaks.[2][4][15][19] If the airport stays near the low-to-mid 20s Celsius, the contract should remain consistent with the current **0%** pricing.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Toronto on August 7? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Kalshi UK, which mirrors the Polymarket order book at 0% fees.

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

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.

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%.