Highest temperature in Seoul on June 27?

Platform comparison

Active sub-markets

Market context

The real-world event in question is the peak daily temperature recorded at Incheon International Airport on 27 June 2026, which will determine the settlement of a prediction market currently implying a 0% chance for any outcome above the lowest bracket. This specific metric relies on data from Wunderground, capturing the highest temperature for all times on that day, rather than a forecasted average.

Historical patterns in Seoul during June show daily highs typically rising from 77°F to 81°F, rarely exceeding 87°F, with recent records in the capital reaching 39.6°C in 2018 and a national peak of 41.0°C in Hongcheon[2][3][7]. While the current crowd-implied probability sits at 0%, Polymarket data suggests a 69% probability for 28°C and 39% for 29°C, revealing a stark divergence between the two platforms where one market dismisses higher temperatures entirely while the other actively prices them[1]. Traders should monitor the Korea Meteorological Administration’s daily bulletins and any sudden shifts in the North Pacific high-pressure system, which drives summer humidity and heat spikes in the region[6][8]. Recent weather history for Seoul in June 2026 indicates a peak of 91°F on 19 June, suggesting that temperatures capable of triggering higher brackets are already plausible within this seasonal window[4].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Seoul on June 27? 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

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?

On Best Prediction Markets UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Best Prediction Markets UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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 Best Prediction Markets UK?

Zero. Best Prediction Markets 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 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.