Highest temperature in Toronto on May 21?

Platform comparison

Active sub-markets

Market context

Toronto Pearson’s highest temperature on 21 May 2026 will be set from the airport station’s final recorded daytime maximum, so the relevant question is whether the day reaches the mid-teens or stays pinned lower under the current late-spring cool spell. As a comparison point, Toronto’s climatology in May is normally much warmer than the current setup: average highs are around 20°C, with daily highs typically rising through the month. But the recent pattern has been notably weak, with Environment and Climate Change Canada and local coverage highlighting unusually low temperatures and only a gradual rebound. That leaves a reading in the low to mid-teens plausible, even though the market’s 0% YES pricing suggests the crowd is effectively dismissing the outcome as inaccessible under the current forecast path.

For traders, the main catalysts are the short-range forecast updates and any shift in wind direction, cloud cover or air mass over southern Ontario before the settlement window closes. A warmer southerly fetch, stronger sunshine, or a faster-than-expected frontal passage could lift the airport reading; persistent northerlies and cloud would cap it. Global News recently reported Toronto highs around 10°C during the same cool stretch, with only a brief recovery expected before another cooler phase, which is the sort of pattern that matters here. From an accessibility angle, the market is open to users facing varying KYC frictions: “no-KYC up to $1,500” typically means small-volume participation without identity checks, while larger deposits or withdrawals can trigger verification. German GlüStV rules may still affect access from Germany, and US CFTC reach remains relevant because it can limit exposure for US persons despite the market’s broader online availability.

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Methodology

This page reviews Highest temperature in Toronto on May 21? across five venues. We show live odds for Polymarket-based markets (sourced from the Polygon order book); for other venues we list platform attributes, since the comparable contracts are not exposed via a public API on every venue. Every CTA points at PolyGram — the application we operate, where you trade directly against the Polymarket order book at 0% fees.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

On PolyGram, 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.

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, PolyGram 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.