Highest temperature in Seoul on June 30?

Platform comparison

Market context

The underlying event is the daily peak temperature recorded at Incheon International Airport on 30 June 2026, which will determine the settlement of this prediction market. Programmatic traders would typically script a bot to pull the Wunderground history endpoint for RKSI, converting the raw Fahrenheit value to Celsius and comparing it against the predefined resolution ranges. With the crowd-implied probability for the highest range sitting at 0%, the market currently assumes the temperature will fall well below the threshold that would trigger a "YES" outcome.

Historical data frames this low probability as statistically sound, given that June highs in Seoul typically range from 77°F to 81°F (25°C to 27°C), rarely exceeding 87°F (31°C) [1]. While South Korea recently recorded its hottest June average since 1973, with a national mean of 22.9°C, and hit a record 41.0°C in Hongcheon, the capital city itself has historically peaked at 39.6°C only during extreme heatwaves in 2018 [2][4][6]. The current 2026 period shows highs reaching 89.2°F (31.8°C) in late June, yet this remains below the extreme thresholds required for the highest market bracket [3].

Traders should monitor the Korea Meteorological Administration’s daily heatwave advisories and any sudden shifts in the East Asian monsoon patterns that could drive temperatures upward. A recent report from Yonhap News confirmed that 59 cities across South Korea experienced record-breaking June heat, with the 30th marking the hottest June day since 1904 [7]. If a high-pressure system stalls over the peninsula, temperatures could spike, though the current 0% probability suggests the market expects the weather to stabilise within the historical norm rather than breach the extreme upper limits.

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 Kalshi Fees, which mirrors the Polymarket order book at 0% fees.

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

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.

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.