Highest temperature in Seoul (Incheon) on August 20?

Platform comparison

Market context

Seoul's summer temperatures regularly exceed 30°C, with August typically the warmest month of the year. The settlement hinges on the highest temperature recorded at Incheon International Airport Station on 20 August 2026, measured in the Weather Underground Daily Observations table rather than the summary high-low section—a distinction that matters when automated systems and manual readings diverge. The 0% crowd probability suggests traders are either absent from this market or treating the outcome as a near-certainty within a specific range, though the lack of volume makes that assessment unreliable.

Historical August data from Incheon shows daily highs clustering between 28–33°C, with extremes occasionally reaching 34–35°C during heat waves. The 2018 Korean heat wave saw temperatures peak above 39°C in some regions, though Incheon's coastal position moderates peaks relative to inland areas. August 2023 recorded a high of 32.4°C at Incheon on the 20th, providing a recent comparable. Traders should note that tropical systems and monsoon patterns significantly influence late-summer temperatures; the timing and intensity of any typhoon approaching the Korean peninsula in mid-August 2026 would be the primary driver of deviation from seasonal norms.

The Korea Meteorological Administration publishes 10-day forecasts approximately weekly, with greater precision arriving in the final 72 hours before the settlement date. Kalshi and Betfair typically offer tighter spreads on weather markets than Polymarket due to higher liquidity and institutional participation, though this particular market's low activity suggests wide bid-ask gaps across all platforms. KYC requirements differ substantially: Kalshi enforces full verification for US residents, whilst Smarkets and Betfair operate with lighter touch approaches in certain jurisdictions.

Methodology

This page compares Highest temperature in Seoul (Incheon) on August 20? 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

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.

FAQ

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.

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.

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.