Highest temperature in Seoul on July 28?

Platform comparison

Market context

Seoul's peak temperature on 28 July 2026 will be measured at Incheon International Airport Station and resolved against historical weather records. The settlement window closes at midday UTC, meaning traders must account for the full calendar day's high before the market locks. This is a straightforward meteorological outcome with no discretionary interpretation—Wunderground's historical data feed provides the single source of truth.

July temperatures in Seoul typically range between 28–32°C, with occasional peaks above 33°C during heat waves. The 0% crowd probability suggests either extreme confidence in a specific temperature band or sparse liquidity on this particular outcome. Cross-platform comparison reveals structural differences: Kalshi's regulatory framework (CFTC-regulated) restricts US-based traders from accessing weather markets outside designated US locations, whereas Polymarket operates globally but with higher KYC friction for certain jurisdictions. Betfair and Smarkets, both UK-regulated, accept broader geographic participation but charge commission on net winnings rather than flat fees, which affects edge calculations on tight temperature ranges.

The Korea Meteorological Administration publishes 10-day forecasts every morning, with updates becoming more granular from 72 hours out. Traders should monitor late-July atmospheric patterns—the East Asian monsoon season and any tropical cyclone activity in the Western Pacific can shift Seoul's highs by 3–5°C. Recent forecasts (available via KMA's English portal) typically become reliable 5–7 days before settlement. The absence of major scheduled events or policy changes means this market hinges entirely on seasonal weather dynamics rather than external announcements.

Methodology

This page compares Highest temperature in Seoul on July 28? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Kalshi Alternative, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Kalshi Alternative has a different geo footprint and routes to Polymarket's order book at 0% fees.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.