Highest temperature in Seattle on July 22?

Platform comparison

Market context

Seattle-Tacoma International Airport’s highest temperature on 22 July 2026 is now effectively a resolved warm-day call: the Polymarket contract is showing **94–95°F at 100%**, with every lower bucket at **0%**, so the crowd is pricing in a hot afternoon rather than an upside surprise or a cooler outcome.[1] In practical terms, that is far above Seattle’s early-morning conditions, which were around **70°F** in the city when AccuWeather reported mostly clear weather and light winds, consistent with a day that can still warm materially after sunrise.[2]

For comparison, the key historical frame is not whether Seattle is capable of heat, but how often the airport actually reaches the upper 90s versus the low-to-mid 90s on midsummer days; the market’s current split implies traders see the airport’s observed maximum as landing in a fairly tight band rather than straddling a threshold. The absence of any price on the cooler bucket suggests the prediction market is treating this less like a binary weather gamble and more like a near-certain range outcome, which is a notable contrast with sportsbook-style lines that typically price the exact temperature range with wider margins when forecast uncertainty remains.

The main catalyst for traders is not a late-breaking news event but the realised weather pattern over the airport’s official observation window, with the final print coming from Wunderground’s Seattle-Tacoma International Airport history page. Any meaningful shift would come from updated local forecast guidance, cloud cover, marine push timing, or an unexpected onshore flow that trims the day’s peak temperature; short-term runway for the market is therefore driven by meteorological dependencies rather than calendar announcements.

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

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

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.

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.

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.