Highest temperature in Seoul (Incheon) on August 4?

Platform comparison

Market context

The key live variable is the **afternoon peak at Incheon Intl Airport Station**, not the feel-like temperature or Seoul city readings. For a programmatic trader, the cleanest approach is to poll the Wunderground daily history endpoint around and after the settlement window, then map the day’s maximum Celsius reading into the market’s published ranges; that avoids relying on third-party summaries or hourly forecasts that can miss a late spike.

The current 0% YES price is hard to reconcile with the published forecast backdrop. Seoul and the greater capital area were flagged for severe heat, with media reporting highs up to 38°C in Seoul and around 37°C in Incheon on 4 August, while AccuWeather’s Seoul August outlook shows daily highs commonly in the low-to-mid 30s Celsius-equivalent range for early August.[1][2][3][4] Historical August context also supports a warm bias: Seoul’s August averages are typically hot and humid, with the month’s record high cited at 38.2°C and typical daytime highs around 28–30°C.[16][17][18][19]

For traders using bots or conditional orders, the practical catalysts are the morning forecast updates, any heat-wave warning extensions, and whether cloud build-up or shower bands arrive earlier than expected. SBS and Asiae both reported scattered showers in parts of the region later on 4 August, but also noted they were unlikely to materially relieve the heat, which matters because a brief convective burst can cap the day’s maximum if it arrives before the natural peak.[2][3] The market is therefore most sensitive to whether Incheon turns out a full clear-sky heating day or gets an early rainfall interruption, rather than to headlines about regional averages.

Sources: 1 · 2 · 3 · 4 · 5

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

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.