Highest temperature in Seoul (Incheon) on August 19?

Platform comparison

Market context

Seoul's highest temperature on 19 August 2026 will be measured at Incheon International Airport Station and reported through Weather Underground's Daily Observations table, with settlement occurring at midday UTC. The market currently shows zero probability assigned to any outcome, suggesting either early-stage liquidity or a data-loading issue across platforms. Kalshi and Polymarket handle temperature resolution differently: Kalshi typically enforces stricter KYC requirements and favours US-centric weather stations, whilst Polymarket's broader international reach has attracted more Seoul-focused traders, though both platforms charge settlement fees that compress margins on narrow temperature bands.

August in Seoul presents predictable meteorological patterns. Historical data from the Korea Meteorological Administration shows mid-August highs averaging 29–31°C, with extremes reaching 35°C during heat waves. The 2018 heatwave pushed Seoul to 39.6°C; more recently, August 2023 peaked at 33.1°C. These precedents suggest the most probable outcome clusters around 30–34°C, yet the 0% crowd probability indicates either insufficient market depth or traders awaiting clearer seasonal forecasts before committing capital.

Traders should monitor the East Asian monsoon pattern and tropical cyclone activity in late July and early August 2026. The Korean Meteorological Administration publishes extended forecasts six weeks ahead; any advisory for above-normal temperatures would shift implied probabilities upward. Smarkets and Betfair's decimal-odds format may reveal sharper probability estimates than Polymarket's binary YES/NO structure, particularly if regional weather specialists begin trading these niche markets.

Methodology

This page compares Highest temperature in Seoul (Incheon) on August 19? 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 UK, 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.

UK Frequently Asked Questions

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.

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.

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.

Polymarket vs Betfair Exchange: which is better for UK prediction trading?

Betfair Exchange offers UKGC regulation, GBP settlement, and potentially tax-free winnings — but focuses on sports and politics only. Polymarket has deeper liquidity, 0% platform fee, global event coverage, and crypto/geopolitical markets Betfair doesn't offer. For UK traders: Betfair for regulated GBP sports markets; Polymarket for broader, global prediction events.

Is Kalshi available in the UK?

Kalshi is a US CFTC-regulated prediction exchange. UK residents can create accounts but must use USD and US payment methods. Kalshi's product range overlaps with Polymarket but with lower liquidity on most contracts. For UK traders, Polymarket typically offers better prices due to higher global volume.