Highest temperature in Seoul on July 21?

Platform comparison

Market context

Seoul is set to experience its peak summer heat on 21 July 2026, with the market betting on whether the Incheon International Airport station will record a temperature exceeding current expectations. The crowd-implied probability of a "YES" outcome sits at 0%, suggesting traders believe extreme heat above the anticipated threshold is virtually impossible for this specific date and location.

Historical data frames this near-zero probability as rational, given that July in Seoul typically sees average highs around 28°C, with 2025 already marking the second-hottest July on record nationwide at 27.1°C average [2]. While humidity often reaches 80% and rain occurs on 43% of days, temperatures rarely breach the extremes required to flip this market, as typical peaks hover near 28°C rather than the higher thresholds implied by a positive outcome [3]. The 0% pricing aligns with the pattern that even record-breaking years like 2025 did not produce daily maximums sufficient to trigger a resolution in the higher range.

Traders should monitor the Korea Meteorological Administration’s daily bulletins for any sudden deviations from the norm, as well as Wunderground’s real-time updates for the Incheon station on the settlement day [2]. No scheduled political debates or campaign-finance disclosures influence this weather event, but an unexpected heatwave declaration or a shift in monsoon patterns could act as the sole catalyst. The market leans entirely on the absence of such anomalies, with the settlement window closing at 12:00 UTC on 21 July 2026, leaving little room for late-day temperature spikes to alter the outcome.

Sources: 1 · 2 · 3

Methodology

This page tracks Highest temperature in Seoul on July 21? 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

For political markets the resolution source is decisive. Polymarket defines a concrete source per contract (e.g. AP, Reuters, official electoral commission) and uses the UMA Optimistic Oracle as the on-chain dispute mechanism. With a clearly defined outcome the USDC payout lands within minutes of the final confirmation.

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.

What resolution source is used for elections?

Polymarket defines the source per contract — usually Associated Press (AP Race Call), Reuters or the official electoral commission. The source is stated in contract details before the market opens.

Can prediction markets influence election outcomes?

Markets reflect expectations rather than create them. Studies show public-facing markets can anchor expectations, but don't influence the underlying outcome. Political markets are information, not advocacy.

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.