Highest temperature in Seoul on June 23?

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Market context

On 23 June 2026, the real-world event determining this market is the highest temperature recorded at Incheon International Airport, measured in degrees Celsius and sourced from Wunderground. In prediction markets, a YES share bets the outcome will fall within a specific temperature range, while a NO share bets it will not; here, the crowd currently implies a 0% chance of a YES outcome, suggesting traders expect the temperature to stay outside the defined range. This stark probability reflects the region’s typical June climate, where daily highs in Seoul average between 25°C and 28°C (77°F–81°F), rarely exceeding 31°C (87°F) [1].

Historical records show South Korea’s summers are intensifying, with 1994, 2018, and 2024 each setting new peak temperatures, and the Korea Meteorological Administration confirming an accelerating rise in heatwave days since 1973 [2]. In 2018, Seoul hit 39.6°C, and the national all-time record reached 41.0°C in Hongcheon in 2024 [3][4]. Yet, even with this warming trend, June 23 has not historically produced extreme outliers in Incheon, where recent data shows a peak of 32.8°C (91°F) on 19 June 2026 [5]. Traders should monitor the North Pacific high-pressure system’s strength, as its intensification could push temperatures toward 35°C (95°F) [7].

Key catalysts include official forecasts from the Korea Meteorological Administration and real-time Wunderground updates for Incheon, which will confirm the day’s maximum temperature. Recent reports flag South Korea as having experienced its hottest summer on record in 2024, with heatwave frequency rising sharply [2]. While no immediate weather announcements are scheduled for 23 June, traders must watch for sudden shifts in humidity or wind patterns that could alter the temperature trajectory. The market’s 0% YES probability remains rational unless an unprecedented heat spike occurs, which historical patterns do not support for this date in Incheon.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Seoul on June 23? on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

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

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.

What does it cost to trade on Prediction Market UK?

Zero. Prediction Market UK routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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.