Highest temperature in Seattle on August 4?

Platform comparison

Market context

Polymarket is pricing this Seattle temperature contract at **0% YES** today, so the market is effectively saying the listed high-temperature band has already been locked in with no room for an alternative outcome. Because settlement is tied to the **Seattle-Tacoma International Airport Station (KSEA)** reading on **Weather Underground**, traders are not betting on a broad Seattle forecast but on the exact daily maximum that appears in that station’s history table once the next day’s first observation is published. Shares sit on Polygon and settle in USDC through conditional tokens, so the relevant question is simply which temperature bucket the final KSEA high falls into, not whether Seattle felt warmer elsewhere in the city.[2][4]

Historically, Seattle’s early-August climate is usually moderate rather than extreme, which is why these daily-high contracts often cluster tightly around the mid-70s to low-80s Fahrenheit in summer. AccuWeather’s August normals for Seattle point to a typical high of about **75°F** and a low near **58°F**, while other monthly climate guides show similar seasonal ranges. That backdrop matters because a 0% reading on the wrong band can still coexist with a settled market if traders have already absorbed the day’s observed high and are waiting only for the source page to finalise it.[1][9]

For a trader watching the last leg of resolution, the main catalyst is not a fresh weather headline but the **data hand-off** from KSEA into Weather Underground’s historical record. Polymarket states that later revisions within the market window can count until the first datapoint for the following date appears, after which changes are ignored, so the key dependency is the timing of Weather Underground’s daily rollover rather than a late forecast update.[2][4] In practical terms, the contract only moves if the source table prints a different final high before that cutoff; otherwise, the on-chain claim in USDC is determined by the published KSEA maximum.

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 Polymarket Scam?, which mirrors the Polymarket order book directly.

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

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket Scam?. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.