Highest temperature in Toronto on June 25?

Platform comparison

Active sub-markets

Market context

The real-world event hinges on the highest temperature recorded at Toronto Pearson International Airport on 25 June 2026, measured in degrees Celsius and resolved via Wunderground data. While the current crowd-implied probability for a specific outcome sits at 0% YES, the market actually assigns a 36% chance to 19°C and 28% to 20°C, keeping 22°C in play as a viable upper bound[1]. This divergence from a flat 0% suggests traders are weighing recent heat anomalies against seasonal norms.

Historically, Toronto Pearson has seen extreme spikes, including a record-breaking 35.8°C recorded recently, which prompted Environment Canada to issue a heat warning for the Greater Toronto Area with humidex values reaching 46[3]. Conversely, a streak of three consecutive days with temperatures above 34°C ended abruptly when the maximum dropped to 30.0°C on 25 June in a prior year, illustrating the volatility of late-June weather patterns[9]. For traders comparing platforms, Polymarket displays these outcomes as decimal odds and implied probabilities, whereas Kalshi and Betfair often emphasise binary implied probabilities with stricter KYC requirements and different fee structures that can alter the effective payout on such volatile weather contracts.

Traders should monitor Environment Canada’s daily heat advisories and the National Weather Service time-series for CYYZ, as overnight lows between 22°C and 25°C offer minimal relief and could push daytime highs higher if cloud cover persists[3]. The settlement window ends at 12:00 UTC on 25 June 2026, meaning any sudden afternoon heatwave will be the final catalyst. On platforms like Smarkets, lower fees might make betting on the 22°C outlier more attractive compared to Polymarket, where liquidity is concentrated on the 19°C and 20°C outcomes[1].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Toronto on June 25? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. Live odds come from the Polymarket order book; the other venues' contract details are maintained manually because their APIs aren't directly comparable. Every CTA routes to Polymarket Alternative, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). Polymarket Alternative routes every trade directly into Polymarket's on-chain settlement, which is why payouts land fastest.

FAQ

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.

What does it cost to trade on Polymarket Alternative?

Zero. Polymarket Alternative 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 Alternative triggers a quick verification flow that finishes in 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.