Highest temperature in Seattle on August 10?

Platform comparison

Market context

Seattle’s temperature is the real-world trigger here, with the market resolving on the **highest reading** logged at Seattle-Tacoma International Airport on 10 August, not the simplified daily high shown elsewhere. The crowd is currently pricing a very low chance of an extreme outcome, which fits Seattle’s late-summer climatology: the average August 10 high is about 77.5°F, while the all-time August 10 record is 98°F and the broader Seattle August record is 99°F[4][14][1].

That historical frame suggests the market’s 0% Yes pricing is really a statement about tail risk, not impossibility. Seattle has produced several warm August 10s in the upper 80s and 90s, but those cases are rare and usually tied to regional heat set-ups rather than ordinary marine-layer weather[14][1]. In that sense, traders should read the current price as leaning heavily on the expectation that the day stays close to seasonal norms rather than on any belief that the record is unreachable.

The main catalyst to watch is the actual airport observation sequence through the settlement window, because Weather Underground’s daily observations table is the source of truth for resolution. Short-term forecast products have recently centred Seattle near the mid-70s, with AccuWeather and Timeanddate both showing roughly 75°F highs and broken-cloud or sunny conditions, which supports the market’s muted temperature outlook rather than a heat spike[8][12]. The key dependency is whether the day’s maximum occurs before the cutoff and whether any late-afternoon warming can add a degree or two above the headline forecast[11][18].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page tracks Highest temperature in Seattle on August 10? across four political prediction venues. Live odds come from the Polymarket order book (the deepest political prediction-market book). Kalshi is the CFTC-regulated US alternative, Betfair the established UK sports-exchange with politics markets, Manifold the open play-money variant. For users geo-blocked from Polymarket directly, brokers like Trump Prediction provide a 0%-fee route into the same order book.

Resolution & payout

Political markets typically settle on official candidate or agency confirmation. Polymarket uses UMA Optimistic Oracle: a proposer posts the outcome with a bond, the two-hour window opens, then the smart contract pays USDC.

Kalshi settles USD via CFTC clearinghouse, with clearly defined resolution sources (e.g. AP race calls for elections). Betfair settles after the official outcome is registered with the league or agency. Manifold is play-money.

UK Frequently Asked Questions

How accurate are political prediction markets?

Historically more accurate than polls. Polymarket's Brier score on US 2024 elections was ~0.11 — better than 538 (~0.14) and every mainstream poll. Markets aggregate information with real skin in the game.

Which platform has the deepest political liquidity?

Polymarket — by far. US 2024 presidential volume was ~$3.5B vs Kalshi (~$200M) and Betfair (~$120M). Where Polymarket is geo-blocked, brokers like Trump Prediction route into the same order book at 0% fees.

Are political prediction markets legal in my country?

It varies. They sit in legal gray areas in most jurisdictions. Polymarket is geo-blocked from US/UK/EU; some broker frontends have a different geo footprint. Trade only with capital you can afford to lose, and only if you understand the legal status in your jurisdiction.

Why do Polymarket and Kalshi differ on elections?

Kalshi must follow CFTC compliance — strict definitions, clear resolution sources, US citizens only with KYC. Polymarket operates globally without CFTC oversight — deeper liquidity, but also higher regulatory risk.

Are UK election prediction markets available from the UK?

Yes. Betfair Exchange and Smarkets offer UKGC-regulated UK election markets (seat counts, party share, constituency results). Polymarket also lists UK election contracts with deeper global liquidity. Betfair winnings are typically tax-free for UK individuals; Polymarket profits are subject to HMRC CGT.