Highest temperature in Seattle on August 9?

Platform comparison

Market context

Seattle’s highest temperature on 9 August has already been described very differently across platforms, which is useful context for the contract. Polymarket showed the market effectively pinned at **76–77°F** with 100% implied probability, while Robinhood’s listed contract for the same event was trading at **93¢** on **74°F**, a meaningful cross-platform gap that suggests either different outcome ladders, different liquidity, or traders interpreting the day’s temperature band in slightly different ways.[1][6] AccuWeather’s monthly view had Seattle at **76°F** for 9 August, and the Weather Underground-style outcome framing matters here because the market settles on the **highest reading in the Daily Observations table**, not the broader Day High & Low summary.[2]

Historically, Seattle’s early-August highs tend to sit in the upper 70s rather than the 80s, with the city’s normal August maximum around **79°F** and recent local reporting showing 9 August observations clustering near that range.[3][5] The current probability structure therefore looks consistent with a modestly warm but not extreme Seattle summer day, which helps explain why the crowd did not price in a wide distribution of hotter outcomes. By contrast, the fact that other sources showed a **77°F** or **78°F** outcome underscores how small forecast differences matter when the contract is banded in narrow Fahrenheit ranges.[1][4]

For traders, the key catalysts are the final station observations at Seattle-Tacoma International Airport and any late revisions before the first datapoint for the next day is published, since the market rules allow updates within that window.[1] The most important dependency is therefore not a forecast headline but the archived airport observation table used by the resolution source, because a one-degree adjustment can move the final bucket. With the market already overwhelmingly resolved in practice by crowd pricing, the main remaining watchpoint is whether the recorded peak lands in the same range as the prevailing exchange quotes or exposes a cross-platform mismatch.[1][6]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Seattle on August 9? 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 Best Prediction Markets, 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

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'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?

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