Highest temperature in Seattle on August 5?

Platform comparison

Market context

Polymarket is pricing the Seattle-Tacoma International Airport high for 5 August at **0% YES** right now, so the contract is effectively saying the crowd sees no meaningful chance of the day’s peak landing in the listed temperature bucket. The market settles against the highest temperature recorded at KSEA on Weather Underground, paid in USDC and resolved through Polygon conditional tokens, so the only number that matters is the final daily high once Weather Underground’s historical table is complete.[2]

That 0% reading is best compared with how Seattle often behaves in early August: the city can post warm afternoons, but the airport station usually sits well below the sort of extreme heat that would move a market into the top buckets. AccuWeather’s August normals and recent nearby forecast outputs point to highs that are often in the upper 70s to low 80s Fahrenheit, while the WeatherSpark and forecast-style sources show that even in August Seattle’s daily highs can vary sharply from one day to the next.[1][6][7][8] For Polymarket users, that means the current price is less a call on “will it be hot?” and more a judgement on whether KSEA prints an unusually strong spike before the close of the observation day.[2]

The main catalysts to watch are the live forecast updates for Seattle-Tacoma, any heat advisories, and the eventual Weather Underground daily history update, because the market resolves only once the first observation from the next calendar day confirms the prior day’s data are final.[2][5] If afternoon forecasts trend upwards or a regional heat advisory appears, traders usually reprice quickly; if the airport stays under the low-80s band through the day, the market remains anchored near the lower outcomes.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Seattle on August 5? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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.

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 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.