Highest temperature in Seoul on July 23?

Platform comparison

Market context

Seoul’s hottest reading on 23 July will be set by the day’s maximum at Incheon Intl Airport Station, with settlement using Wunderground’s daily history page rather than a citywide official average. In Polymarket terms, the current book is priced as a temperature bin, with **30°C or higher** the frontrunner at **51%** and **29°C** next at **41%**, so the market is still split between a modestly warm day and a slightly cooler outcome.[1]

For context, late-July weather in South Korea typically sits around **30°C** for highs, with lows near **23°C**, so a result in the upper 20s or around 30°C is consistent with seasonal norms rather than an extreme.[2] That helps explain why a zeroed-out market elsewhere may not reflect the underlying climatology: on platforms that quote decimal odds, such as Betfair or Smarkets, the same view would appear as price rather than implied probability, while Polymarket displays the probability directly and Kalshi’s contracts are listed in cents, making comparison less immediate across books.

The main catalysts are short-range forecast updates, monsoon positioning, and any overnight changes in cloud cover or rainfall that can cap the daytime maximum. For traders comparing venues, the practical differences are KYC reach and fee treatment: exchange-style books can be more accessible in some jurisdictions, while prediction-market platforms often depend on venue-specific onboarding and, in some cases, tighter US-focused compliance rules. For this specific market, the key risk is that the highest temperature is determined by a single station reading, so even small forecast shifts can move the dominant bin quickly.[1][2]

Sources: 1 · 2

Methodology

This page compares Highest temperature in Seoul on July 23? 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 Robinhood Prediction Markets, 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

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

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. Robinhood Prediction Markets 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.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Robinhood Prediction Markets offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.