Highest temperature in Seoul on July 4?

Platform comparison

Market context

The underlying real-world event is whether Seoul’s highest temperature on 4 July 2026 will reach 29°C, a threshold that currently carries a 30.5% implied probability on Lines.com, while Polymarket’s conditional tokens overwhelmingly favour 28°C at 92%. On-chain, USDC settles these outcomes on Polygon, with the market closing at noon KST today. The crowd-implied probability of 0% YES on your specific contract suggests traders see 29°C as highly unlikely for Incheon Airport, despite Seoul’s broader July climate.

Historical July data frames this low probability: Seoul’s average July maximum is 27.7°C, with daily highs typically ranging 23–30°C, while Incheon Airport often records slightly cooler temperatures than the city centre due to coastal exposure [5][8]. The 29°C bracket is a minority call across platforms, and six other temperature ranges share the remaining probability, meaning no single outcome dominates [1]. Monsoon conditions (Jangma), which peak in July with 319mm rainfall, further suppress extreme heat, making 29°C an outlier rather than a norm [4].

Traders should monitor the Korea Meteorological Administration’s short-range forecasts for 4 July, which update daily highs between 9 AM and 5 PM, and watch for sudden shifts in humidity or cloud cover that could alter the peak temperature [7]. Recent weather reports indicate Seoul’s July highs will range 81–94°F (27–34°C), but Incheon’s coastal location may cap the maximum below 29°C [6]. No major heatwave announcements are scheduled, and the monsoon’s heavy, concentrated rainfalls in July remain the primary dependency for temperature suppression [4].

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 Legit?, 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 Legit?. 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 Legit? 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.