Highest temperature in Seattle on August 10?

Platform comparison

Market context

Seattle’s August 10 temperature at Sea-Tac is a straightforward weather settle, but the current pricing still looks notably cautious: Polymarket shows **74–75°F** as the favourite at **47%**, with **72–73°F** next at **28%** and **76–77°F** at **15%**, while the market-wide **0% YES** read suggests no broad conviction beyond the centred mid-70s band.[1] That sits close to public forecast guidance around the date, with AccuWeather and timeanddate both indicating a high near **75°F** and only modest day-to-day volatility in the low-to-mid 70s.[3][12] Against the climatology, that is unremarkable: Seattle’s average August high is about **77.5°F**, and the long-run record for 10 August is **98°F**, so the contract is about the exact daily band rather than an extreme outcome.[5][15]

For comparison, the market is trading far below the sort of tail risk that would matter in a heat event. Seattle’s all-time August high is **99°F**, set on 9 August 1981, and the city’s broader climate record shows genuinely exceptional heat is rare even in the warm season.[2][16] That means a sportsbook-style line, if one were offered, would likely cluster around the same mid-70s range rather than the top end of the distribution; the prediction market’s pricing implies a fairly tight consensus, not a meaningful premium for a breakout hot day. The relevant benchmark is therefore not the historical record, but how often Seattle-Tacoma Airport lands a single-degree bucket above or below forecast.

The main catalysts are ordinary forecast updates rather than event-driven news: the National Weather Service airport observations, the day-before model refresh, and any late shift in marine cloud cover or inland wind direction that can push Sea-Tac temperatures a degree or two either way.[14] Since this market settles on the **Daily Observations** table at Weather Underground rather than the headline high/low summary, traders will care most about the *observed* maximum at Seattle-Tacoma International Airport during the settlement window, not the rounded forecast figure shown elsewhere.[11] Political, economic, or scheduling news is unlikely to matter here; the dependency is almost entirely on local temperature timing and whether the afternoon peak lands inside the current **74–75°F** consensus band.[1][11]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Best Prediction Markets, which mirrors the Polymarket order book directly.

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.

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.

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.