Highest temperature in Seoul on July 5?

Platform comparison

Market context

The contract for Seoul’s highest temperature on 5 July 2026 sits at 0% YES on Polymarket today, priced in USDC on the Polygon network using conditional tokens. This implies the market expects the temperature to fall outside the defined range, likely because the range is set for extreme heat that historical data suggests is improbable for this specific date. Yet, the underlying real-world event is straightforward: July in Seoul is hot and humid, with average highs near 28–30°C, often feeling above 34°C due to monsoon moisture [1][2].

Historically, early July in Seoul has seen record-breaking heat. In 2023, Seoul reached 37.8°C on 8 July, the highest early-July temperature in 117 years of records [8][9]. While 5 July is slightly earlier, the monsoon season (late June to mid-July) can produce sudden, intense heatwaves when rain clears and humidity rises [1]. Traders should note that such spikes are not routine but are possible, especially if the rainy period ends abruptly before the 5th.

Key catalysts include the Korea Meteorological Administration’s short-range forecasts, which currently show mostly cloudy conditions with a 20% precipitation probability and temperatures around 27–29°C [5]. A sudden shift to clear skies and high-pressure systems could trigger rapid warming. Traders should monitor daily updates from AccuWeather and Wunderground, as well as any announcements about heatwave advisories from Seoul authorities, which often precede extreme temperature events [4]. The resolution source is Wunderground’s highest recorded temperature for Incheon Intl Airport Station on 5 July 2026, so any data anomaly there could affect settlement.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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 PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.