Highest temperature in Seattle on August 4?

Platform comparison

Market context

Polymarket has this contract trading as a temperature-range bet on the Seattle-Tacoma International Airport reading, with the crowd currently pricing **0%** for **YES** on the outcome in question. On Polygon, traders are buying and selling conditional tokens with USDC, so the quote reflects the market’s live view of which final Wunderground range will contain the day’s peak rather than a simple forecast of whether Seattle will be hot or cool.

That 0% reading is best read against the market’s own range ladder and the platform’s current price structure, not as a statement that the event is impossible. The nearby outcomes on the market page are clustered around the mid-80s Fahrenheit, which implies traders are treating a late-summer warm spell as the base case, while still leaving room for small changes in the final airport maximum as hourly observations come in. For this kind of contract, the relevant comparison is usually to nearby daily-high markets and the Seattle August climatology: Seattle’s August normals are typically mild, but the upper end of summer heat can still push the airport station into the low-to-mid 80s, which is where the pricing is concentrated.

A trader watching this one should focus on the weather setup into the settlement window: National Weather Service forecast updates, any shift in the marine layer, and whether inland heat or a sea-breeze onshore flow becomes dominant near Sea-Tac. Because resolution uses the highest temperature shown by Wunderground for the airport station, the practical catalyst is not the whole-day narrative but the final hourly high and whether later observations revise the peak before the first datapoint for the next day is published. The contract’s value will therefore move most on forecast changes, not on after-the-fact commentary, and the settlement mechanics matter as much as the weather itself.

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Methodology

This page reviews Highest temperature in Seattle on August 4? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

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

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'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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.