Pronóstico: Highest temperature in Seattle on August 9?

Platform comparison

Market context

Polymarket is pricing this Seattle heat contract at **100% for 76-77°F**, with the rest of the board effectively at zero, so the market is already treating a mid-70s outcome as the settled consensus in USDC on Polygon. On Polymarket’s own terms, shares in the winning range redeem for $1 once the market resolves via the Weather Underground daily observations for Seattle-Tacoma International Airport, not the simpler day-high summary, and late revisions only matter until the next day’s first datapoint is published.[1]

That sort of near-certain pricing is easiest to read against Seattle’s August climate, where the long-run daily high sits around the upper 70s and the month’s historic peak is 99°F, reached on 9 August 1960 and 1981.[4][16] The key comparison for traders is that the contract is not asking whether Seattle gets “hot” in a generic sense, but whether the airport station prints a specific observed maximum within the listed band. A 77°F observed high on 9 August sits very close to forecast normals and squarely inside the range that weather services and historical climatology suggest is most common for a clear summer day in Seattle.[4][6][7]

For a Polymarket user, the practical catalyst is not a policy announcement but the observation process itself: the morning and afternoon Sea-Tac readings, any local marine push that caps heating, and whether Weather Underground posts a later revision before the following day’s first record locks the figure in place.[1][13] Forecast services had already pointed to a mostly sunny, pleasant day with a high near 76°F, which helps explain why the contract is priced so tightly around the mid-70s despite Seattle’s occasional outlier heat.[11][12]

Sources: 1 · 2 · 3 · 4 · 5

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.

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 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.

Do I need to KYC for this market?

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