Highest temperature in Toronto on June 25?

Platform comparison

Active sub-markets

Market context

The real-world event centres on the highest temperature recorded at Toronto Pearson International Airport on 25 June 2026, measured in degrees Celsius. A power-user evaluating this market programmatically would first query Wunderground’s historical API for the station CYYZ, filtering for the daily maximum across all timestamps on that date. The current crowd-implied probability of 0% for a “YES” outcome suggests the market expects the temperature to fall outside the defined range, likely due to prevailing cool conditions.

Historical data frames this probability sharply: June 25 has seen extreme heat in recent years, including a record 35.8°C in 2023 and a scorching 36°C in 2026’s July 13 event[3][9]. Yet today’s forecast shows only 25°C with thunderstorms and 80% precipitation probability, a stark contrast to past heatwaves[1][2]. This divergence explains the 0% pricing; traders are betting on rain suppressing temperatures rather than a repeat of record-breaking heat.

Key catalysts include Environment Canada’s heat warnings and real-time precipitation updates, which directly influence thermal outcomes[3]. A trader should monitor the National Weather Service’s live timeseries for CYYZ, watching for sudden shifts in dew point or humidity that could alter the maximum[4]. Recent news confirms heat advisories persist in the GTA, but today’s thundery showers override those risks[2]. Programmatically, conditional orders should trigger if Wunderground’s hourly data dips below 20°C, locking in the 0% position before settlement on 2026-06-25T12:00:00Z.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Toronto on June 25? on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

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

Where can I trade this market with the lowest fees?

On Polymarket Bot UK, which mirrors the Polymarket order book at 0% fees. 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.

What does it cost to trade on Polymarket Bot UK?

Zero. Polymarket Bot UK routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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?

Not under $1,500 of lifetime trading volume. Above that threshold, Polymarket Bot UK triggers a quick verification flow that finishes in minutes.