Highest temperature in Seattle on July 23?

Platform comparison

Market context

Seattle-Tacoma International Airport’s hottest reading on 23 July will be settled against a very local, single-day weather print rather than a broad seasonal average, so the key question is whether conditions support a brief warm spike or something closer to a standard July high. Seattle’s July climate is usually mild, with typical daytime highs around 75°F and cool nights, which means the market’s 0% YES price is effectively anchored to the view that an extreme outcome is unlikely rather than impossible.[1]

That framing is better read against comparable July conditions than against a headline forecast for the city centre. Historical climate guides put Seattle’s average July high in the low-to-mid 70s Fahrenheit, and NOAA’s Sea-Tac time-series page provides the airport station data that will ultimately matter for settlement, which can diverge from other local readings.[1][2] In that sense, a 0% implied probability suggests traders are treating the outcome as outside the normal range for the date, with the market leaning heavily on climatology rather than any one-off weather model wobble.[1][2]

The main catalyst to watch is the short-range forecast chain for Sea-Tac: any late-run warm advection, reduced marine influence, or clear-sky, high-sun conditions would be the kind of setup that could push the day’s maximum into a higher range. Traders should also watch official National Weather Service updates and airport-specific observations, since those are more relevant to the settlement source than citywide headlines or regional averages.[2] The catalyst here is therefore *weather guidance*, not campaign-style event timing; the move would come from forecast revisions, not scheduled announcements.[2]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Political prediction markets differ structurally from sports betting: thinner liquidity, longer settlement windows, higher sensitivity to single news events. This page shows the live Polymarket quote for Highest temperature in Seattle on July 23? plus platform attributes for the three reference venues, so you can see at a glance where the deepest market for this question sits.

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.

FAQ

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 Election Predictions UK route into the same order book at 0% fees.

How fast do political markets react to news?

High-liquidity markets move within seconds to minutes. A Trump tweet on the economy can shift the "Trump 2024" market 2-5 points before mainstream media has written anything.

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.

Which political events have the biggest volume?

US Presidential election, party nominations (DNC/RNC), Senate majorities, individual state outcomes (Pennsylvania, Michigan, Wisconsin), and major European elections. Peak markets reach $50-500M per event.