Highest temperature in Seattle on July 22?

Platform comparison

Market context

The underlying event is the **highest temperature recorded at Seattle-Tacoma International Airport on 22 July 2026**, measured by the Wunderground daily history page used for settlement. In plain terms, a **YES** share pays if the day’s maximum temperature lands in the market’s specified range, while a **NO** share pays if it lands elsewhere; the current crowd view is a 0% YES probability, which implies traders see that range as effectively excluded.

For context, weather markets are usually read against the actual forecast path rather than a single headline temperature. On a summer day in Seattle, small shifts in cloud cover, marine influence, or inland heat can move the final high enough to change which band wins, so traders often care more about the distribution of possible highs than about the current temperature itself. The market’s current 0% reading is a very strong statement, but in weather contracts it mainly means the crowd believes the settled outcome is already fixed by the observed forecast and the range definition, not that the atmosphere is literally certain.

What matters next is any forecast update that could change the day’s recorded maximum before the settlement window closes, especially changes to the expected high temperature, timing of peak warmth, or cloud cover over the airport. For this specific contract, the key dependency is the station reading at KSEA rather than broader Seattle conditions, so traders should watch airport-level forecasts and any late-day weather guidance that might affect the observed maximum before the day ends.

Sources: 1 · 2

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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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 Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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.

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.