Highest temperature in Seoul on July 4?

Platform comparison

Market context

The underlying event is the peak daytime temperature recorded at Incheon International Airport on 4 July 2026, which will determine the settlement of this prediction market. Historical data from the Korea Meteorological Administration shows that early July highs in Seoul typically cluster between 27°C and 31°C, with the 29°C bracket sitting at the centre of this range. Recent records indicate volatility; South Korea experienced its second-hottest July since 1973 in 2025, and Seoul reached 37.7°C in early July 2025, a figure 117 years high. Despite this wide historical window where six other temperature brackets share the remaining probability, the current crowd-implied probability of 0% for the 29°C outcome suggests traders are confident the high will land outside this specific range, likely favouring higher extremes given the recent trend of record-breaking heat.

A power-user approaching this market programmatically would monitor real-time inputs from Wunderground for the Incheon station, specifically tracking the hourly temperature curve as settlement nears noon KST. The primary catalyst is the absence of a cooling system event, meaning the market hinges entirely on atmospheric conditions and the potential for a tropical night to persist into the following day, a phenomenon that reached 22 nights in July 2025. Traders should watch for any sudden shifts in the Asian monsoon patterns or local heatwave announcements from the Korea Meteorological Administration, as these dependencies directly influence the peak temperature. Recent reporting from Anadolu Ajansı confirms that Seoul has already broken 117-year records for early July temperatures, reinforcing the likelihood that the 2026 high will exceed the 29°C threshold rather than sit within it.

Sources: 1 · 2 · 3 · 4 · 5

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 Polymarket Review UK, 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 Polymarket Review UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.

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.

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.