Highest temperature in Seoul on June 5?

Market context

On 5 June 2026, the highest temperature recorded at Incheon International Airport Station will determine which range this market settles into. The settlement uses Wunderground's historical weather data for that specific location, requiring traders to assess Seoul's early summer conditions with precision. The 0% crowd probability suggests either extreme confidence in a particular outcome or minimal trading activity on this specific contract.

Seoul's June temperatures typically range from 20–28°C, with occasional peaks above 30°C during early heat waves. Historical data from June 2023 and 2024 shows high temperatures between 24–29°C on comparable dates, providing a baseline for assessing likelihood across temperature bands. The current zero probability on YES outcomes indicates either that the market's range structure makes all listed options implausible to traders, or that liquidity remains too sparse to establish meaningful odds. Kalshi's weather markets typically attract more volume than comparable offerings on Polymarket or Betfair, though this particular Seoul contract shows limited engagement across platforms.

Traders should monitor Korea Meteorological Administration forecasts released in late May 2026, which will clarify whether atmospheric patterns favour typical early-summer conditions or an anomalous heat event. The settlement window closes at 12:00 UTC on 5 June, giving traders only until midday to adjust positions based on morning temperature readings. Differences in fee structures—Kalshi's flat-rate model versus Polymarket's percentage-based approach—may affect position sizing for traders betting on marginal temperature outcomes where expected value depends on precise probability calibration.

Methodology

We read Highest temperature in Seoul on June 5? 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

Resolution source: This market settles from the official publication at https://www.wunderground.com/history/daily/kr/incheon/RKSI. A proposer submits the result to the UMA Optimistic Oracle on Polygon, the two-hour challenge window opens, and the smart contract pays out in USDC.

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

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

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.

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. PolyGram 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.