Highest temperature in Seoul on June 30?

Platform comparison

Market context

The underlying real-world event is the highest temperature recorded on 30 June 2026 at Incheon International Airport, near Seoul, measured in degrees Celsius. Long-term averages place Seoul’s June daytime maximums around 26°C, with a typical range of 19–28°C and moderate humidity before the monsoon intensifies [1][2]. Historical data from June 2026 shows a peak of 34.0°C on 19 June, indicating that extreme heat can occur, though late June often sees cooling as the rainy season begins [9]. Given this pattern, the current crowd-implied probability of 0% YES suggests traders believe the temperature will fall within a lower range, possibly below a threshold that would trigger a “high” outcome, aligning with the expectation of milder conditions as the month closes [1][7].

Traders should monitor daily forecasts from the Korea Meteorological Administration, particularly updates on cloud cover, precipitation, and wind patterns that could suppress temperatures on 30 June [4]. A key catalyst is the onset of the monsoon, which typically starts in late June and brings frequent afternoon showers that limit daytime heating [2][6]. Recent weather reports note that while early June feels like extended spring, increasing humidity and rain toward the end of the month often reduce peak temperatures [2]. On-chain, this market settles on Polygon using USDC, with conditional tokens reflecting the probability of each temperature range; the 0% YES price implies the market expects no breach of the upper threshold, likely due to anticipated rain or cloud cover on the settlement day [4][6].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Seoul on June 30? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like PolyGram 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.