Highest temperature in Seoul on June 30?

Platform comparison

Market context

The underlying event is the peak daily temperature at Incheon International Airport on 30 June 2026, a metric that will determine the settlement of this prediction market. Historical data for Seoul in June shows daily highs typically rising from 77°F to 81°F, rarely exceeding 87°F, yet recent years have shattered these norms with record-breaking heatwaves[1]. South Korea recorded its hottest June average since 1973 last year, and 2025 saw 59 cities hit record-breaking temperatures, with one day reaching 25.8°C as the hottest June day in modern records[4][7]. Even Seoul itself has breached 39.6°C in past summers, proving that the current 0% crowd-implied probability for higher ranges may be underestimating the volatility of a warming climate[6].

A power-user approaching this programmatically must monitor real-time Wunderground feeds for the Incheon station, as the market resolves strictly on the highest temperature recorded for all times on that day[2]. The primary catalyst is the ongoing intensification of the East Asian summer monsoon and associated heat domes, which have driven all-time heat records to 41.0°C in Hongcheon recently[2]. Traders should watch the Korea Meteorological Administration’s daily heatwave advisories and any sudden shifts in shortwave solar energy, which is gradually decreasing but remains potent enough to spike temperatures[1]. Given the trend of record-breaking June heat, a conditional order strategy focusing on the upper temperature bands could capture value if the forecast aligns with the 85°F to 91°F range predicted for June 2026[8].

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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.

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.

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.