Highest temperature in Seattle on August 4?

Platform comparison

Market context

Seattle’s temperature on 4 August will be set by the highest reading recorded at Seattle-Tacoma International Airport, and this market pays in USDC on-chain if the outcome falls into the relevant Fahrenheit band. A 0% implied chance effectively says the crowd sees the listed range as priced out, so even a modestly hot afternoon can force a repricing because the contract resolves on the day’s peak, not the evening close.

The historical frame is straightforward: early August in Seattle is usually one of the warmer and drier stretches of the year, but the city still spends much of the month in the 70s Fahrenheit rather than in sustained heat-wave territory. AccuWeather’s August page for Seattle shows an average high around 77°F, while other August climate pages describe the month as typically sunny and relatively dry.[1][7][5] That matters for range-based contracts, because a forecast that looks only slightly above average can still leave several adjacent bins live, especially if a marine layer burns off late or offshore warmth arrives during the afternoon peak.

For traders, the main catalysts are the official forecast updates, any coastal smoke or wind shifts, and the live airport observations that can move the last-mile settlement bin. The National Weather Service forecast referenced in market materials pointed to a high near 82°F with sunny conditions, light northerly winds, and patchy smoke, which is the kind of setup that can keep the distribution clustered in the low-80s unless conditions change materially.[3] On the crypto side, the relevant lens is whether broader BTC and ETH risk appetite is strong enough to draw liquidity into small-market weather books; when spot is stable and funding is muted, these niche contracts often trade more on forecast revisions than on macro flows.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reads Highest temperature in Seattle on August 4? on-chain. Polymarket's quote comes directly from the Polygon order book — the only comparable venue with on-chain settlement. Kalshi (USD, off-chain), Betfair (GBP/EUR, off-chain) and Manifold (play-money) are listed alongside for venue context. Every CTA routes to BTC Prediction, which mirrors the Polymarket order book directly.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

FAQ

What are crypto prediction markets?

Crypto prediction markets are on-chain smart contracts where you buy YES or NO shares on a future crypto event (e.g. "BTC above $100k by year-end"). The market price between 0¢ and 100¢ is the implied probability.

How does UMA secure the resolution?

The UMA Optimistic Oracle uses a bond system: a proposer posts a bond, a two-hour challenge window opens. On dispute the losing side forfeits the bond — financial incentive for honest resolution.

How volatile are crypto prediction markets?

Crypto markets react to spot prices — a 5% BTC move typically shifts a "BTC above X by date" market 10-20%. Polymarket crypto market liquidity is usually six-figure USD, sufficient for active trading.

Which crypto markets exist on Polymarket?

Currently active markets include BTC/ETH/SOL price targets, halving dates, ETF approvals, hard-fork outcomes and Layer-2 TVL thresholds. The list updates weekly; biggest volume sits on BTC and ETH price forecasts.

Are crypto prediction markets taxable in the US?

In the US, prediction market gains are typically treated as ordinary income or short-term capital gains depending on holding period. Consult a tax professional for your specific situation — we cannot provide tax advice.