Highest temperature in Seoul on July 9?

Platform comparison

Market context

Seoul’s July heat is a tangible reality, with daytime temperatures typically hovering between 25°C and 30°C, occasionally nudging higher in humid conditions. The current crowd-implied probability of 0% for a specific high temperature range suggests traders are either misreading the market’s resolution criteria or betting on an extreme outlier that contradicts historical norms. Incheon International Airport, where the market resolves, sits just west of Seoul and shares similar climatic patterns, though coastal influences can slightly moderate peak highs compared to the city centre.

Historical data frames this probability sharply: July 2025 saw South Korea record its second-hottest July since 1973, averaging 27.1°C, while early July 2026 already hit a record 37.8°C in Seoul itself[5][9]. Traders collectively estimate a 34.5% chance the official high lands exactly at 26°C, indicating the 0% YES probability likely targets a different, perhaps much higher, threshold[3]. A power-user approaching this programmatically would script a bot to pull Wunderground’s hourly data for Incheon, cross-referencing it with Korea Meteorological Administration alerts to identify conditional order triggers based on real-time temperature spikes.

Key catalysts include monsoon progression and urban heatwave announcements, which can abruptly shift daily highs. Recent reports note Seoul experienced its longest stretch of tropical nights in 117 years, with temperatures failing to drop below 25°C overnight, a dependency that could sustain elevated daytime peaks[8]. Traders should monitor the Korea Meteorological Administration’s heatwave schedules and Wunderground’s live updates for Incheon, as a sudden monsoon burst could suppress highs, while sustained humidity may push them toward record territory. The market’s resolution hinges on precise, time-stamped data, making real-time monitoring essential for any conditional order strategy.

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Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket Review UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Review UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.