Highest temperature in Seoul on July 10?

Platform comparison

Market context

On 10 July 2026, the highest temperature recorded at Incheon International Airport will determine the outcome of a prediction market focused on Seoul’s heat. The current crowd-implied probability for a “YES” resolution is 0%, yet Polymarket traders assign a 36% chance to 28°C and 24% to 29°C as the most likely outcomes, revealing a stark divergence between platform-implied odds and the binary market’s pricing.

Historical data frames this discrepancy: July 8, 2026, reached 37.8°C in South Korea, the hottest early July day in over a century, while Seoul itself hit 37.7°C, beating records from 1908 [2][7]. Tropical nights have persisted above 25°C for 22 consecutive days, breaking a century-old record and indicating sustained thermal stress [3][5]. Average July highs in Seoul range from 81°F to 85°F (27.2°C to 29.4°C), rarely exceeding 91°F [6], suggesting that 28–29°C remains plausible despite the 0% binary pricing.

Traders should monitor real-time Wunderground updates for Incheon, as the market resolves solely on its highest daily reading [1]. The Korea Meteorological Administration’s ongoing heatwave advisories and any shifts in cloud cover or wind patterns could alter the day’s peak temperature [2]. With settlement ending at 12:00 UTC on 10 July, the next 10 hours of weather data will be decisive, and any deviation from the 28–29°C range could invalidate the binary market’s current 0% stance.

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

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 Kalshi vs Polymarket. 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 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 Kalshi vs Polymarket trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.