Highest temperature in Seattle on July 23?

Platform comparison

Market context

Seattle-Tacoma International Airport’s highest temperature on 23 July 2026 will ultimately be set by the day’s observed peak at KSEA, so the market is really pricing a single-station afternoon high rather than the broader city-wide feel. The crowd-implied probability of 0% YES suggests the contract is being treated as effectively outside the reachable range, but that looks misaligned with Seattle’s July climatology: typical July highs are around 75°F, with warmth often landing in the mid-70s rather than anything extreme[1][3].

That means the benchmark for reading this market is the distribution of Seattle summer highs, not a one-off heatwave narrative. July is usually dry and seasonally mild, with long daylight hours and relatively light winds, which helps explain why highs often cluster in the 70s and occasionally push into the low 80s when regional ridging builds[1][3]. By contrast, broad media attention tends to focus on rare heat events, such as the Western Washington heat advisory and mid-80s temperatures reported in Seattle during a recent hot spell, which are useful as upside comparables but are not the base case for an airport high on an ordinary July day[4].

For traders, the main catalysts are the evolving synoptic set-up, marine-layer persistence, and any heat advisory or forecast-shift headlines from the National Weather Service or local outlets in the days before settlement; those factors can move expectations more than long-range seasonal averages[2][4]. I could not verify any sportsbook line for this exact weather contract, so there is no clear cross-platform price to compare against the prediction market or a published analyst consensus here[2].

Sources: 1 · 2 · 3 · 4

Methodology

This page reviews Highest temperature in Seattle on July 23? 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

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 Best Prediction Markets. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.