Highest temperature in Seoul (Incheon) on August 12?

Platform comparison

Market context

Seoul's maximum temperature on 12 August 2026 will be recorded at Incheon International Airport Station and resolved against Weather Underground's Daily Observations table rather than summary figures—a distinction that matters when platforms diverge on data sourcing. The 0% implied probability reflects either sparse liquidity or traders' confidence that the market's specific resolution criteria will be difficult to satisfy, though August typically brings Seoul's hottest readings of the year.

Historical August temperatures at Incheon show a median high around 29–30°C, with extremes reaching 34–35°C during heat waves. The 2018 Korean heat wave saw Incheon peak at 34.5°C; more recently, August 2023 recorded highs of 32–33°C across multiple days. These precedents establish the plausible range, though any given day's maximum depends heavily on synoptic patterns—monsoon influence, high-pressure systems, and cloud cover all shift outcomes materially. The current crowd assessment suggests either scepticism about extreme heat materialising that specific day or uncertainty about how Weather Underground's Daily Observations table will capture readings versus other reporting standards.

Traders should monitor Korea Meteorological Administration forecasts from early August 2026, which typically issue 10-day outlooks by late July. Typhoon activity in the Western Pacific during summer months can suppress temperatures or trigger sudden spikes; the 2024 typhoon season demonstrated how late-summer systems reshape Korean weather within days. Platform differences matter here: Kalshi's binary structure and Polymarket's range-based approach will price tail probabilities differently, whilst Betfair's decimal odds format may reveal sharper disagreement on sub-30°C versus above-33°C scenarios if liquidity develops.

Methodology

We read Highest temperature in Seoul (Incheon) on August 12? 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

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.

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.