Highest temperature in Seoul on July 4?

Platform comparison

Market context

On 4 July 2026, the highest temperature recorded at Incheon International Airport will determine the outcome of a prediction market focused on Seoul’s peak heat, with the current crowd-implied probability of hitting exactly 29°C sitting at 0% YES. This near-zero stance contrasts sharply with broader market data, where the 29°C bracket trades at a 30.5% implied probability on Lines.com, suggesting a significant divergence between this specific contract’s pricing and the wider consensus on Seoul’s early July thermal range.

Historical records show that early July highs in Seoul typically cluster between 27°C and 31°C, though the window is genuinely wide, with extremes reaching 37.7°C in 2023—the highest early July temperature in 117 years. The Korea Meteorological Administration notes that 29°C sits at the centre of this range, making it the single most likely outcome statistically, yet still a minority call given that six other temperature brackets share the remaining probability. Recent data from Climate Central confirms South Korea endured its second-hottest July since 1973, reinforcing the volatility traders should expect.

Traders must monitor real-time forecasts from the Korea Meteorological Administration before the noon KST resolution, as thin volume below $1M means prices can shift sharply on updated data. A recent Anadolu Ajansı report highlights that nighttime temperatures in Seoul recently broke a century-old record, with 22 consecutive nights above 25°C, indicating sustained heat pressure that could push daytime highs beyond the 29°C bracket. With the settlement window ending 12:00 UTC on 4 July, any sudden KMA announcement could decisively alter the odds, particularly if tropical night conditions persist into the following day.

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Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Kalshi vs Polymarket, which mirrors the Polymarket order book directly.

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 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.

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.