Highest temperature in Seoul on July 11?

Platform comparison

Market context

Seoul faces a critical heat check on 11 July 2026, as traders assess whether the Incheon International Airport station will record temperatures exceeding historical early-July norms. The current 0% implied probability for a “YES” outcome suggests the market expects temperatures to stay within lower ranges, yet recent climate patterns in South Korea show a marked upward trend in summer extremes.

Historical data frames this probability with caution: Seoul hit 37.8°C in early July 2023, the hottest reading in 117 years, while the nation’s all-time record reached 41.0°C in Hongcheon in 2023[1][2]. July averages in Seoul typically climb to 85°F (29.4°C), rarely exceeding 91°F (32.8°C), but 2025 saw Anseong reach 40.6°C and Seoul hit 37.7°C in late July, marking the highest early-July temperature since 1908[3][5][6]. These outliers suggest that a 0% probability may understate the risk of a sudden heat spike.

Traders should monitor the Korea Meteorological Administration’s daily heatwave alerts and the absence of significant rainfall through 6 August, as forecasts indicate temperatures will remain above average with persistent tropical nights[5]. No major weather announcements are scheduled for 11 July, but the dependency on real-time Wunderground data for the Incheon station means resolution hinges on precise, minute-by-minute logging rather than regional averages. On platforms like Kalshi or Betfair, decimal odds would reflect this uncertainty more transparently than Polymarket’s implied probability, while fee structures and KYC requirements vary significantly across these books.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Seoul on July 11? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.

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

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.

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.

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. Polymarket Alternative 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.